Online Assessment DSA / Coding Machine Coding Low-Level Design System Design Tech Deep-Dive Hiring Manager Behavioral / HR

Round 06 · 60 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

1Password
How does React reconciliation / the diffing algorithm work?
FrontendNew Grad / JuniorMedium◆ Commonly asked
#react#fiber
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1Password
Explain how Promises work and implement Promise.all.
FrontendNew Grad / JuniorMedium◆ Commonly asked
#javascript#async
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1Password
Explain hydration and the cost of client vs server rendering.
FrontendNew Grad / JuniorHard◆ Commonly asked
#ssr#perf
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1Password
How would you design and version a public REST API?
BackendMidMedium◆ Commonly asked
#api-design
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1Password
How do you retry without amplifying load?
BackendMidHard◆ Commonly asked
#reliability
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1Password
What is backpressure and how do you handle it?
BackendMidHard◆ Commonly asked
#streaming#reliability
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1Password
Explain WeakMap/WeakSet and when to use them.
Full-stackSeniorMedium◆ Commonly asked
#javascript
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1Password
What is a deadlock and how do you avoid one?
Full-stackSeniorHard◆ Commonly asked
#concurrency
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1Password
Difference between CSS Grid and Flexbox — when to use each.
Full-stackSeniorEasy◆ Commonly asked
#css#layout
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1Password
Explain the CSS box model and box-sizing.
FrontendSeniorEasy◆ Commonly asked
#css
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1Password
What is the virtual DOM and why does it help?
FrontendSeniorMedium◆ Commonly asked
#react
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1Password
What are React keys and why do they matter?
FrontendSeniorEasy◆ Commonly asked
#react
PracticeGeeksforGeeks Search
Abridge
Explain optimistic vs pessimistic locking.
Full-stackMidHard◆ Commonly asked
#databases
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Abridge
How do you prevent and detect N+1 queries?
Full-stackMidMedium◆ Commonly asked
#databases#orm
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Abridge
How do circuit breakers and bulkheads improve resilience?
Full-stackMidMedium◆ Commonly asked
#reliability
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Abridge
How do you run a zero-downtime database migration?
BackendNew Grad / JuniorHard◆ Commonly asked
#databases
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Abridge
How do you design an idempotency-key system for payments?
BackendNew Grad / JuniorHard◆ Commonly asked
#idempotency#payments
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Abridge
Explain how you handle concurrency / race conditions.
BackendNew Grad / JuniorHard◆ Commonly asked
#concurrency
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Abridge
How does the browser critical rendering path work?
FrontendNew Grad / JuniorMedium◆ Commonly asked
#browser#perf
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Abridge
Explain server components vs client components.
FrontendNew Grad / JuniorHard◆ Commonly asked
#react#ssr
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Abridge
How does React reconciliation / the diffing algorithm work?
FrontendNew Grad / JuniorMedium◆ Commonly asked
#react#fiber
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Accenture
Explain CPU scheduling algorithms: FCFS, SJF and round robin.
Full-stackInternMedium◆ Commonly asked
#os
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Accenture
Explain the static and final keywords in Java.
Full-stackInternEasy◆ Commonly asked
#java
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Accenture
Difference between C and C++.
Full-stackInternEasy◆ Commonly asked
#c
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Accenture
Explain the layers of the OSI model.
Full-stackInternEasy◆ Commonly asked
#networking
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Accenture
Explain database normalization and its normal forms.
BackendSeniorMedium◆ Commonly asked
#dbms
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Accenture
What happens when you type a URL into a browser?
BackendSeniorMedium◆ Commonly asked
#networking
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Accenture
What is a pointer? Explain pointer arithmetic in C.
BackendSeniorMedium◆ Commonly asked
#c
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Accenture
What is indexing in a database and when does it help?
BackendSeniorMedium◆ Commonly asked
#dbms
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Accenture
Write a SQL query to find the second-highest salary.
BackendNew Grad / JuniorMedium◆ Commonly asked
#sql
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Accenture
What is a deadlock and how do you prevent it?
BackendNew Grad / JuniorMedium◆ Commonly asked
#os
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Accenture
Explain the ACID properties of a transaction.
BackendNew Grad / JuniorMedium◆ Commonly asked
#dbms
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Accenture
Explain your final-year project architecture and your role in it.
BackendNew Grad / JuniorEasy◆ Commonly asked
#project
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Accenture
Difference between DELETE, TRUNCATE and DROP.
Full-stackNew Grad / JuniorEasy◆ Commonly asked
#sql
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Accenture
What is polymorphism? Compile-time vs runtime.
Full-stackNew Grad / JuniorEasy◆ Commonly asked
#oops
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Accenture
Difference between a process and a thread.
Full-stackNew Grad / JuniorEasy◆ Commonly asked
#os
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Accenture
Explain Java collections: List, Set and Map.
Full-stackNew Grad / JuniorMedium◆ Commonly asked
#java
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Accenture
Difference between abstraction and encapsulation.
BackendInternEasy◆ Commonly asked
#oops
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Accenture
Explain primary key, foreign key, unique key and candidate key.
BackendInternEasy◆ Commonly asked
#dbms
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Accenture
Difference between TCP and UDP.
BackendInternEasy◆ Commonly asked
#networking
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Accenture
Difference between stack and heap memory.
BackendInternEasy◆ Commonly asked
#fundamentals
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Acko
How does a bloom filter work and when would you use one?
BackendSeniorMedium◆ Commonly asked
#data-structures#probabilistic
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Acko
How does a write-ahead log guarantee durability?
BackendSeniorHard◆ Commonly asked
#databases
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Acko
What is a deadlock and how do you avoid one?
BackendSeniorHard◆ Commonly asked
#concurrency
PracticeGeeksforGeeks Search
Acko
What are React keys and why do they matter?
FrontendMidEasy◆ Commonly asked
#react
PracticeGeeksforGeeks Search
Acko
Explain the difference between == and === and coercion.
FrontendMidEasy◆ Commonly asked
#javascript
PracticeGeeksforGeeks Search
Acko
Explain how CSS-in-JS differs from utility CSS.
FrontendMidEasy◆ Commonly asked
#css
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Acko
How would you design and version a public REST API?
Full-stackMidMedium◆ Commonly asked
#api-design
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Acko
Explain how you handle concurrency / race conditions.
Full-stackMidHard◆ Commonly asked
#concurrency
PracticeGeeksforGeeks Search
Acko
Explain WeakMap/WeakSet and when to use them.
Full-stackMidMedium◆ Commonly asked
#javascript
PracticeGeeksforGeeks Search
Acko
Message queues vs pub/sub — when to use each.
BackendNew Grad / JuniorMedium◆ Commonly asked
#messaging
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Acko
How does the OAuth 2.0 authorization-code flow work?
BackendNew Grad / JuniorMedium◆ Commonly asked
#auth#security
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Acko
How do circuit breakers and bulkheads improve resilience?
BackendNew Grad / JuniorMedium◆ Commonly asked
#reliability
PracticeGeeksforGeeks Search
Activision Blizzard
Closures and the module pattern — with an example.
Full-stackNew Grad / JuniorEasy◆ Commonly asked
#javascript#closures
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Activision Blizzard
Explain Core Web Vitals (LCP, CLS, INP) and how to improve them.
Full-stackNew Grad / JuniorHard◆ Commonly asked
#perf
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Activision Blizzard
Difference between at-least-once and exactly-once delivery.
Full-stackNew Grad / JuniorHard◆ Commonly asked
#messaging
PracticeGeeksforGeeks Search
Activision Blizzard
How do you prevent and detect N+1 queries?
BackendSeniorMedium◆ Commonly asked
#databases#orm
PracticeGeeksforGeeks Search
Activision Blizzard
Message queues vs pub/sub — when to use each.
BackendSeniorMedium◆ Commonly asked
#messaging
PracticeGeeksforGeeks Search
Activision Blizzard
Explain eventual consistency with a real example.
BackendSeniorHard◆ Commonly asked
#distributed
PracticeGeeksforGeeks Search
Activision Blizzard
Explain the difference between SSR, SSG, and ISR.
FrontendMidMedium◆ Commonly asked
#ssr#rendering
PracticeGeeksforGeeks Search

More practice · open source

Topic banks

488extra questions on this round's topics, imported from MIT-licensed open-source repositories. These are topic questions — they are not attributed to any company.

React (in depth)60 questions

What is React?
What is the history behind React’s evolution?
What are the major features of React?
What is JSX?
What is the difference between an Element and a Component?
How do you create components in React?
When should you use a Class Component over a Function Component?
What are Pure Components?
What is state in React?
What are props in React?
What is the difference between state and props?
What is the difference between HTML and React event handling?
What are synthetic events in React?
What are inline conditional expressions?
What is the "key" prop and what is its benefit when used in arrays of elements?
What is the Virtual DOM?
How does the Virtual DOM work?
What is the difference between Shadow DOM and Virtual DOM?
What is React Fiber?
What is the main goal of React Fiber?
What are controlled components?
What are uncontrolled components?
What is the difference between createElement and cloneElement?
What is Lifting State Up in React?
What are Higher-Order Components?
What is the children prop?
How do you write comments in React?
What is reconciliation?
Does the lazy function support named exports?
Why does React use className instead of the class attribute?
What are Fragments?
Why are Fragments better than container divs?
What are portals in React?
What are stateless components?
What are stateful components?
How do you apply validation to props in React?
What are the advantages of React?
What are the limitations of React?
What are the recommended ways for static type checking?
What is the use of the react-dom package?
What is ReactDOMServer?
How do you use innerHTML in React?
How do you apply styles in React?
How are events different in React?
What is the impact of using indexes as keys?
How do you conditionally render components?
Why do we need to be careful when spreading props on DOM elements?
How do you memoize a component?
How do you implement Server-Side Rendering (SSR)?
How do you enable production mode in React?
Do Hooks replace render props and higher-order components?
What is a switching component?
What are React Mixins?
What are the pointer events supported in React?
Why should component names start with a capital letter?
Are custom DOM attributes supported in React v16?
How do you loop inside JSX?
How do you access props within attribute quotes?
What is a React PropType array with shape?
How do you conditionally apply class attributes?

⎇ sudheerj/reactjs-interview-questions · MIT ↗

HTML50 questions

Write a HTML table tag sequence that outputs the following
What is an iframe and how it works?
Explain meta tags in HTML
What is the purpose of the alt attribute on images?
What is a self closing tag?
What is the difference between span and div?
How Can I Get Indexed Better by Search Engines?
How can you highlight text in HTML?
Briefly describe the correct usage of the following HTML5 semantic elements: `<header>`, `<article>`, `<section>`, `<footer>`
What is Character Encoding?
What were some of the key goals and motivations for the HTML5 specification?
How do you change the direction of html text?
What is WebSQL?
Explain the difference between block elements and inline elements
What is an optional tag?
When is it appropriate to use the small element?
What is the difference between `<section>` and `<div>`?
What are Web Workers?
What does a DOCTYPE do?
How do you serve a page with content in multiple languages?
What is the purpose of cache busting and how can you achieve it?
Can a web page contain multiple <header> elements? What about <footer> elements?
What are `data-` attributes good for?
What are `defer` and `async` attributes on a `<script>` tag?
What is the DOM?
Discuss the differences between an HTML specification and a browser’s implementation thereof.
What are some differences that XHTML has compared to HTML?
Where and why is the `rel="noopener"` attribute used?
What is HTML5 Web Storage? Explain `localStorage` and `sessionStorage`.
Describe the difference between a 'cookie', 'sessionStorage' and 'localStorage'.
How do you set IE compatibility mode?
What's new in HTML 5?
Have you used different HTML templating languages before?
Explain the difference between cookies, session and local storage
Explain almost standard, full standard and quirks mode
Describe the difference between `<script>`, `<script async>` and `<script defer>`.
What is WebP?
What is progressive rendering?
Why you would use a `srcset` attribute in an image tag? Explain the process the browser uses when evaluating the content of this attribute.
Why to use HTML5 semantic tags?
HTML Markup Validity
Why do I need a doctype and what does it do?
What's the difference between Full Standard, Almost Standard and Quirks Mode?
What kind of things must you be wary of when designing or developing for multilingual sites?
How would you select svg or canvas for your site?
What are the building blocks of HTML5?
What is an HTML preprocessor and are you using it?
What is the purpose of 'main' element?
What are Web Components?
What is accessibility & ARIA role means in a web application?

⎇ FAQGURU/FAQGURU · MIT ↗

JavaScript50 questions

What is Coercion in JavaScript?
What is typeof operator?
What is the object type?
Explain arrays in JavaScript
Explain equality in JavaScript
What is Scope in JavaScript?
What is let keyword in JavaScript?
Explain what a callback function is and provide a simple example.
What is strict mode?
What does "use strict" do?
What is a Polyfill?
How would you check if a number is an integer?
Explain Values and Types in JavaScript
Being told that an unsorted array contains (n - 1) of n consecutive numbers (where the bounds are defined), find the missing number in O(n) time
Remove duplicates of an array and return an array of only unique elements
Given a string, reverse each word in the sentence
Write a function that would allow you to do this.
Implement enqueue and dequeue using only two stacks
How would you use a closure to create a private counter?
Explain Null and Undefined in JavaScript
Explain event bubbling and how one may prevent it
How to check if an object is an array or not? Provide some code.
Write a "mul" function which will properly when invoked as below syntax.
How to empty an array in JavaScript?
How to compare two objects in JavaScript?
Given an array of integers, find the largest difference between two elements such that the element of lesser value must come before the greater element
Find the intersection of two arrays. An intersection would be the common elements that exists within both arrays. In this case, these elements should be unique!
Write a function that would allow you to do this
Given two strings, return true if they are anagrams of one another
Check if a given string is a palindrome. Case sensitivity should be taken into account.
What is the difference between a shim and a polyfill?
What will the following code output?
Could you explain the difference between ES5 and ES6
What is IIFEs (Immediately Invoked Function Expressions)?
What will be the output of the following code?
Provide some examples of non-boolean value coercion to a boolean one
Explain the difference between "undefined" and "not defined" in JavaScript
What is the drawback of creating true private in JavaScript?
What is the difference between anonymous and named functions?
Given an array of integers, find the largest product yielded from three of the integers
Describe closure concept in JavaScript as best as you could
Write a recursive function that returns the binary string of a given decimal number
What is “closure” in javascript? Provide an example?
Explain what is hoisting in Javascript
Given an integer, determine if it is a power of 2. If so, return that number, else return -1
Describe the JS module design pattern
How would you create a private variable in JavaScript?
Explain the Prototype Design Pattern
Write a recursive function that performs a binary search
Create a function that will evaluate if a given expression has balanced parentheses using stacks

⎇ FAQGURU/FAQGURU · MIT ↗

MongoDB50 questions

Does Mongodb Support Foreign Key Constraints?
Which are the most important features of MongoDB?
Explain what is MongoDB?
How many indexes does MongoDB create by default for a new collection?
Compare SQL databases and MongoDB at a high level.
What Is Replication In MongoDB?
What is “Namespace” in MongoDB?
If you remove an object attribute, is it deleted from the database?
Why does Profiler use in MongoDB?
What is BSON in MongoDB?
Does MongoDB need a lot space of Random Access Memory (RAM)?
How is data stored in MongoDB?
Mention the command to insert a document in a database called school and collection called persons.
What are Indexes in MongoDB?
What is a replica set?
Can you create an index on an array field in MongoDB? If yes, what happens in this case?
When should we embed one document within another in MongoDB?
How is MongoDB better than other SQL databases?
Should I normalize my data before storing it in MongoDB?
What is use of capped collection in MongoDB?
What does MongoDB not being ACID compliant really mean?
How to query MongoDB with %like%?
How do I perform the SQL JOIN equivalent in MongoDB?
When to use MongoDB or other document oriented database systems?
What is the difference between MongoDB and MySQL?
How can you achieve primary key - foreign key relationships in MongoDB?
Does MongoDB pushes the writes to disk immediately or lazily?
If you remove a document from database, does MongoDB remove it from disk?
What is the difference b/w MongoDB and CouchDB?
What is sharding?
What are NoSQL databases? What are the different types of NoSQL databases?
Explain the structure of ObjectID in MongoDB
What is a covered query in MongoDB?
How can I combine data from multiple collections into one collection?
Find objects between two dates MongoDB
How to query MongoDB with “like”?
Is there an “upsert” option in the mongodb insert command?
What is oplog?
How can you achieve transaction and locking in MongoDB?
What do you understand by NoSQL databases? Explain.
What is Sharding in MongoDB? Explain.
Can one MongoDB operation lock more than one databases? If yes, how?
Mention the command to check whether you are on the master server or not.
Why are MongoDB data files large in size?
Does MongoDB support ACID transaction management and locking functionalities?
Why MongoDB is not preferred over a 32-bit system?
What is Aggregation in MongoDB?
How replication works in MongoDB?
By default, MongoDB writes and reads data from both primary and secondary replica sets. True or False.
How does MongoDB provide concurrency?

⎇ FAQGURU/FAQGURU · MIT ↗

Node.js50 questions

What is Node.js?
What is npm?
What are the two types of API functions in Node.js?
What are Event Listeners?
What is global installation of dependencies?
What are the core modules of Node,js?
What is an error-first callback?
How you can monitor a file for modifications in Node.js ?
Could we run an external process with Node.js?
What's the difference between operational and programmer errors?
What are the benefits of using Node.js?
What is the difference between Nodejs, AJAX, and jQuery?
How to make Post request in Node.js?
What is Callback Hell?
If Node.js is single threaded then how it handles concurrency?
What do you mean by Asynchronous API?
What are the key features of Node.js?
What is control flow function?
Is Node a single threaded application?
List out the differences between AngularJS and NodeJS?
What is the purpose of setTimeout function?
What is REPL in context of Node?
How can you avoid callback hells?
What is Callback?
What's the event loop?
What is a blocking code?
How Node prevents blocking code?
What is Event Loop?
What is stream and what are types of streams available in Node.js?
What is Event Emmitter?
How to avoid callback hell in Node.js?
What is purpose of Buffer class in Node?
When should I use EventEmitter?
What is difference between synchronous and asynchronous method of fs module?
What are streams?
What is the preferred method of resolving unhandled exceptions in Node.js?
When should we use Node.js?
How to use Buffer in Node.js?
What is Chaining in Node?
What are the global objects of Node.js?
Explain how does Node.js work?
How does Node.js handle child threads?
How can you listen on port 80 with Node?
When to not use Node.js?
Is Node.js entirely based on a single-thread?
Does Node.js support multi-core platforms? And is it capable of utilizing all the cores?
Why to use Buffers instead of binary strings to handle binary data ?
What's a stub? Name a use case.
What tools can be used to assure consistent code style?
How to gracefully Shutdown Node.js Server?

⎇ FAQGURU/FAQGURU · MIT ↗

React50 questions

What is the use of refs?
What is JEST?
What are the advantages of ReactJS?
How to write comments in ReactJS?
What is context?
What is virtual DOM?
How does React work?
What is React?
What is props in ReactJS?
What are the major features of ReactJS?
What is ReactJS?
What are props in React?
How would you write an inline style in React?
What are the limitations of ReactJS?
What’s the difference between an "Element" and a "Component" in React?
What are stateful components?
What are stateless components?
What are portals in ReactJS?
What are fragments?
Why is it necessary to capitalize the components?
What is reconciliation?
What is the purpose of using super constructor with props argument?
When to use a Class Component over a Functional Component?
What are the advantages of using React?
What are Higher-Order components?
What are controlled components?
What is the difference between a Presentational component and a Container component?
How to create refs?
What are the differences between a class component and functional component?
What do you like about React?
What is inline conditional expressions?
What is the difference between state and props?
How is React different from AngularJS (1.x)?
What happens during the lifecycle of a React component?
How to pass a parameter to an event handler or callback?
What is the purpose of callback function as an argument of setState?
What is the difference between component and container in react Redux?
What is state in ReactJS?
How to create components in ReactJS?
What is the difference between Element and Component?
What are refs used for in React?
When rendering a list what is a key and what is it's purpose?
What is JSX?
Where in a React component should you make an AJAX request?
What is the difference between React Native and React?
Describe how events are handled in React.
What is Flux?
Where is the state kept in a React + Redux application?
What is the point of Redux?
What is Flow?

⎇ FAQGURU/FAQGURU · MIT ↗

SQL50 questions

What is PRIMARY KEY?
Define a temp table
What is a view?
What’s the difference between a local temp table and a global temp table?
What is blocking?
What is the difference between WHERE clause and HAVING clause?
What is FOREIGN KEY?
What is Normalization?
How can a column with a default value be added to an existing table?
What is DEFAULT?
What is the difference between inner and outer join?
Discuss INNER JOIN ON vs WHERE clause
What are the difference between clustered and a non-clustered index?
How do I perform an IF…THEN in an SQL SELECT?
Finding duplicate values in a SQL table
How does a hash table index work?
What are the advantages of using Stored Procedures?
What is Denormalization?
How to select first 5 records from a table?
Define ACID Properties
How a database index can help performance?
What is the difference between UNION and UNION ALL?
What is a cursor how does it work?
How do I UPDATE from a SELECT in SQL Server?
What is the difference between “INNER JOIN” and “OUTER JOIN”?
Is table size reduced, when you delete data from the table?
Explain Function vs. Stored Procedure in SQL Server
What are row constructors?
What is the difference between JOIN and UNION?
What is collation?
Describe the difference between truncate and delete
How does B-trees index work?
What are statistics?
How deadlock is resolved?
What is the difference among UNION, MINUS and INTERSECT?
What is a filegroup?
How can I do an UPDATE statement with JOIN in SQL?
How does truncate and delete operation effect Identity?
Explain a usage difference between user defined functions and stored procedures
What is a linked server?
How can we transpose a table using SQL (changing rows to column or vice-versa) ?
What would happen without an index?
Name types of Triggers
What are DMV's and DMF's?
What's the difference between a primary key and a unique key?
Delete duplicate values in a SQL table
What is the cost of having a database index?
How to generate row number in SQL Without ROWNUM
Explain the difference between exclusive lock and update lock
Insert results of a stored procedure into a temporary table

⎇ FAQGURU/FAQGURU · MIT ↗

AWS44 questions

What is AWS?
Explain the key components of AWS?
What is buckets in AWS?
What is AWS Cloudfront?
What do you mean by AMI? What does it include?
How can I download a file from EC2?
Is it possible to clone a EC2 instance data?
What is AWS Data Pipeline?
Explain the features of Amazon EC2 services
What is the connection between AMI and Instance?
Are S3 buckets region specific?
What is AWS Direct Connect?
What is AWS EBS?
What is AWS Lambda?
What is AWS DynamoDB?
What is AWS EMR?
Is data stored in S3 is always encrypted?
Can we attach single EBS to multiple EC2s same time?
What is AWS API gateway?
What are the security best practices for Amazon EC2 instances?
Can I automatically start and terminate my Amazon instance using Amazon API?
Can we still continue working on EBS while creating snapshot of it?
What is AWS Auto Scaling?
What is AWS Auto Scaling group?
What is the maximum size of a single S3 object?
What is AWS bucket policy?
Does AWS has the option for vertical "auto" scaling of EC2 instance?
What is AWS WAF? What are the potential benefits of using WAF?
How to get the instance id from within an EC2 instance?
What is AWS Cloudwatch?
What is the difference between Amazon EC2 and AWS Elastic Beanstalk?
How many storage options are there for EC2 Instance?
What is AWS Route 53?
How would you implement vertical auto scaling of EC2 instance?
What is Amazon Kinesis?
How to find a region from within an EC2 instance?
Where are EC2 snapshots stored?
When should one use the following: Amazon EC2, Google App Engine, Microsoft Azure and Salesforce.com?
When to use Amazon CloudFront and when S3?
Our EC2 micro instance occasionally runs out of memory. Other than using a larger instance size, what else can be done?
What is difference between Lightsail and EC2?
What is the underlying hypervisor for EC2?
How to safely upgrade an Amazon EC2 instance from t1.micro to large?
[↑] Back to top

⎇ FAQGURU/FAQGURU · MIT ↗

CSS39 questions

Explain the three main ways to apply CSS styles to a web page
What is CSS?
What is DOM (Document Object Model) and how is it linked to CSS?
Explain the CSS “box model” and the layout components that it consists of
What is a CSS rule?
What existing CSS frameworks have you used locally, or in production? How would you change/improve them?
Have you played around with the new CSS Flexbox or Grid specs?
What is the difference between classes and IDs in CSS?
Describe floats and how they work
Explain CSS sprites, and how you would implement them on a page or site.
How would you approach fixing browser-specific styling issues?
What is CSS preprocessor and why to user one?
Have you ever worked with retina graphics? If so, when and what techniques did you use?
How is responsive design different from adaptive design?
How to create a zebra striped table with CSS?
What’s the difference between “resetting” and “normalizing” CSS? Which would you choose, and why?
How does CSS actually work (under the hood of browser)?
Explain your understanding of the box model and how you would tell the browser in CSS to render your layout in different box models.
What is CSS selectors? Name some.
Explain the usage of "table-layout" property
Describe pseudo-elements and discuss what they are used for.
What does Accessibility (a11y) mean?
What are the advantages/disadvantages of using CSS preprocessors?
What is a Grid System in CSS?
What's the difference between a `relative`, `fixed`, `absolute` and `static`ally positioned element?
Explain the purpose of clearing floats in CSS
How do you optimize your webpages for print?
Have you ever used a grid system, and if so, what do you prefer?
What are the different ways to visually hide content (and make it available only for screen readers)?
Describe z-index and how a stacking context is formed
What does * { box-sizing: border-box; } do? What are its advantages?
Can you explain the difference between coding a website to be responsive versus using a mobile-first strategy?
Explain the basic rules of CSS Specificity
Is there any reason you'd want to use `translate()` instead of `absolute` positioning, or vice-versa? And why?
What the code fragment has the greater CSS specificity?
What clearfix methods do you know? Provide some examples.
How to style every element which has an adjacent item right before it?
Write down a selector that will match any links end in .zip, .ZIP, .Zip etc...
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⎇ FAQGURU/FAQGURU · MIT ↗

Redux31 questions

What is Flux?
What is Redux DevTools?
What is Redux?
Do you need to keepIs all component states in Redux store?
How to add multiple middlewares to Redux?
What are Redux selectors and Why to use them?
What are the features of Redux DevTools?
What are reducers in redux?
What is Redux Thunk?
What is the difference between React context and React redux?
What is redux-saga?
What are the core principles of Redux?
How to set initial state in Redux?
How to structure Redux top level directories?
What are the downsides of Redux over Flux?
What are the differences between redux-saga and redux-thunk?
What is the purpose of the constants in Redux?
How to use connect from react redux?
Are there any similarities between Redux and RxJS?
What is Redux form?
What are the main features of Redux Form?
How to access redux store outside a react component?
What is the proper way to access Redux store?
What are the differences between call and put in redux-saga?
Whats the purpose of at (@) symbol in the redux connect decorator?
How to make Ajax request in Redux?
Why are Redux state functions called as reducers?
How to reset state in redux?
What is the mental model of redux-saga?
How Relay is different from Redux?
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GraphQL14 questions

What is GraphQL?
Is GraphQL a Database Technology?
Is GraphQL only for React / Javascript Developers?
How to do Error Handling?
Where is GraphQL useful?
What is GraphQL schema?
How to do Authentication and Authorization?
Does GraphQL Support Offline Usage?
How to do Server-side Caching?
List the key concepts of the GraphQL query language
Explain the main difference between REST and GraphQL
What kind of operations could GraphQL schema have?
Are there any disadvantages to GraphQL?
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Topic banks

488extra questions on this round's topics, imported from MIT-licensed open-source repositories. These are topic questions — they are not attributed to any company.

React (in depth)60 questions

What is React?
What is the history behind React’s evolution?
What are the major features of React?
What is JSX?
What is the difference between an Element and a Component?
How do you create components in React?
When should you use a Class Component over a Function Component?
What are Pure Components?
What is state in React?
What are props in React?
What is the difference between state and props?
What is the difference between HTML and React event handling?
What are synthetic events in React?
What are inline conditional expressions?
What is the "key" prop and what is its benefit when used in arrays of elements?
What is the Virtual DOM?
How does the Virtual DOM work?
What is the difference between Shadow DOM and Virtual DOM?
What is React Fiber?
What is the main goal of React Fiber?
What are controlled components?
What are uncontrolled components?
What is the difference between createElement and cloneElement?
What is Lifting State Up in React?
What are Higher-Order Components?
What is the children prop?
How do you write comments in React?
What is reconciliation?
Does the lazy function support named exports?
Why does React use className instead of the class attribute?
What are Fragments?
Why are Fragments better than container divs?
What are portals in React?
What are stateless components?
What are stateful components?
How do you apply validation to props in React?
What are the advantages of React?
What are the limitations of React?
What are the recommended ways for static type checking?
What is the use of the react-dom package?
What is ReactDOMServer?
How do you use innerHTML in React?
How do you apply styles in React?
How are events different in React?
What is the impact of using indexes as keys?
How do you conditionally render components?
Why do we need to be careful when spreading props on DOM elements?
How do you memoize a component?
How do you implement Server-Side Rendering (SSR)?
How do you enable production mode in React?
Do Hooks replace render props and higher-order components?
What is a switching component?
What are React Mixins?
What are the pointer events supported in React?
Why should component names start with a capital letter?
Are custom DOM attributes supported in React v16?
How do you loop inside JSX?
How do you access props within attribute quotes?
What is a React PropType array with shape?
How do you conditionally apply class attributes?

⎇ sudheerj/reactjs-interview-questions · MIT ↗

HTML50 questions

Write a HTML table tag sequence that outputs the following
What is an iframe and how it works?
Explain meta tags in HTML
What is the purpose of the alt attribute on images?
What is a self closing tag?
What is the difference between span and div?
How Can I Get Indexed Better by Search Engines?
How can you highlight text in HTML?
Briefly describe the correct usage of the following HTML5 semantic elements: `<header>`, `<article>`, `<section>`, `<footer>`
What is Character Encoding?
What were some of the key goals and motivations for the HTML5 specification?
How do you change the direction of html text?
What is WebSQL?
Explain the difference between block elements and inline elements
What is an optional tag?
When is it appropriate to use the small element?
What is the difference between `<section>` and `<div>`?
What are Web Workers?
What does a DOCTYPE do?
How do you serve a page with content in multiple languages?
What is the purpose of cache busting and how can you achieve it?
Can a web page contain multiple <header> elements? What about <footer> elements?
What are `data-` attributes good for?
What are `defer` and `async` attributes on a `<script>` tag?
What is the DOM?
Discuss the differences between an HTML specification and a browser’s implementation thereof.
What are some differences that XHTML has compared to HTML?
Where and why is the `rel="noopener"` attribute used?
What is HTML5 Web Storage? Explain `localStorage` and `sessionStorage`.
Describe the difference between a 'cookie', 'sessionStorage' and 'localStorage'.
How do you set IE compatibility mode?
What's new in HTML 5?
Have you used different HTML templating languages before?
Explain the difference between cookies, session and local storage
Explain almost standard, full standard and quirks mode
Describe the difference between `<script>`, `<script async>` and `<script defer>`.
What is WebP?
What is progressive rendering?
Why you would use a `srcset` attribute in an image tag? Explain the process the browser uses when evaluating the content of this attribute.
Why to use HTML5 semantic tags?
HTML Markup Validity
Why do I need a doctype and what does it do?
What's the difference between Full Standard, Almost Standard and Quirks Mode?
What kind of things must you be wary of when designing or developing for multilingual sites?
How would you select svg or canvas for your site?
What are the building blocks of HTML5?
What is an HTML preprocessor and are you using it?
What is the purpose of 'main' element?
What are Web Components?
What is accessibility & ARIA role means in a web application?

⎇ FAQGURU/FAQGURU · MIT ↗

JavaScript50 questions

What is Coercion in JavaScript?
What is typeof operator?
What is the object type?
Explain arrays in JavaScript
Explain equality in JavaScript
What is Scope in JavaScript?
What is let keyword in JavaScript?
Explain what a callback function is and provide a simple example.
What is strict mode?
What does "use strict" do?
What is a Polyfill?
How would you check if a number is an integer?
Explain Values and Types in JavaScript
Being told that an unsorted array contains (n - 1) of n consecutive numbers (where the bounds are defined), find the missing number in O(n) time
Remove duplicates of an array and return an array of only unique elements
Given a string, reverse each word in the sentence
Write a function that would allow you to do this.
Implement enqueue and dequeue using only two stacks
How would you use a closure to create a private counter?
Explain Null and Undefined in JavaScript
Explain event bubbling and how one may prevent it
How to check if an object is an array or not? Provide some code.
Write a "mul" function which will properly when invoked as below syntax.
How to empty an array in JavaScript?
How to compare two objects in JavaScript?
Given an array of integers, find the largest difference between two elements such that the element of lesser value must come before the greater element
Find the intersection of two arrays. An intersection would be the common elements that exists within both arrays. In this case, these elements should be unique!
Write a function that would allow you to do this
Given two strings, return true if they are anagrams of one another
Check if a given string is a palindrome. Case sensitivity should be taken into account.
What is the difference between a shim and a polyfill?
What will the following code output?
Could you explain the difference between ES5 and ES6
What is IIFEs (Immediately Invoked Function Expressions)?
What will be the output of the following code?
Provide some examples of non-boolean value coercion to a boolean one
Explain the difference between "undefined" and "not defined" in JavaScript
What is the drawback of creating true private in JavaScript?
What is the difference between anonymous and named functions?
Given an array of integers, find the largest product yielded from three of the integers
Describe closure concept in JavaScript as best as you could
Write a recursive function that returns the binary string of a given decimal number
What is “closure” in javascript? Provide an example?
Explain what is hoisting in Javascript
Given an integer, determine if it is a power of 2. If so, return that number, else return -1
Describe the JS module design pattern
How would you create a private variable in JavaScript?
Explain the Prototype Design Pattern
Write a recursive function that performs a binary search
Create a function that will evaluate if a given expression has balanced parentheses using stacks

⎇ FAQGURU/FAQGURU · MIT ↗

MongoDB50 questions

Does Mongodb Support Foreign Key Constraints?
Which are the most important features of MongoDB?
Explain what is MongoDB?
How many indexes does MongoDB create by default for a new collection?
Compare SQL databases and MongoDB at a high level.
What Is Replication In MongoDB?
What is “Namespace” in MongoDB?
If you remove an object attribute, is it deleted from the database?
Why does Profiler use in MongoDB?
What is BSON in MongoDB?
Does MongoDB need a lot space of Random Access Memory (RAM)?
How is data stored in MongoDB?
Mention the command to insert a document in a database called school and collection called persons.
What are Indexes in MongoDB?
What is a replica set?
Can you create an index on an array field in MongoDB? If yes, what happens in this case?
When should we embed one document within another in MongoDB?
How is MongoDB better than other SQL databases?
Should I normalize my data before storing it in MongoDB?
What is use of capped collection in MongoDB?
What does MongoDB not being ACID compliant really mean?
How to query MongoDB with %like%?
How do I perform the SQL JOIN equivalent in MongoDB?
When to use MongoDB or other document oriented database systems?
What is the difference between MongoDB and MySQL?
How can you achieve primary key - foreign key relationships in MongoDB?
Does MongoDB pushes the writes to disk immediately or lazily?
If you remove a document from database, does MongoDB remove it from disk?
What is the difference b/w MongoDB and CouchDB?
What is sharding?
What are NoSQL databases? What are the different types of NoSQL databases?
Explain the structure of ObjectID in MongoDB
What is a covered query in MongoDB?
How can I combine data from multiple collections into one collection?
Find objects between two dates MongoDB
How to query MongoDB with “like”?
Is there an “upsert” option in the mongodb insert command?
What is oplog?
How can you achieve transaction and locking in MongoDB?
What do you understand by NoSQL databases? Explain.
What is Sharding in MongoDB? Explain.
Can one MongoDB operation lock more than one databases? If yes, how?
Mention the command to check whether you are on the master server or not.
Why are MongoDB data files large in size?
Does MongoDB support ACID transaction management and locking functionalities?
Why MongoDB is not preferred over a 32-bit system?
What is Aggregation in MongoDB?
How replication works in MongoDB?
By default, MongoDB writes and reads data from both primary and secondary replica sets. True or False.
How does MongoDB provide concurrency?

⎇ FAQGURU/FAQGURU · MIT ↗

Node.js50 questions

What is Node.js?
What is npm?
What are the two types of API functions in Node.js?
What are Event Listeners?
What is global installation of dependencies?
What are the core modules of Node,js?
What is an error-first callback?
How you can monitor a file for modifications in Node.js ?
Could we run an external process with Node.js?
What's the difference between operational and programmer errors?
What are the benefits of using Node.js?
What is the difference between Nodejs, AJAX, and jQuery?
How to make Post request in Node.js?
What is Callback Hell?
If Node.js is single threaded then how it handles concurrency?
What do you mean by Asynchronous API?
What are the key features of Node.js?
What is control flow function?
Is Node a single threaded application?
List out the differences between AngularJS and NodeJS?
What is the purpose of setTimeout function?
What is REPL in context of Node?
How can you avoid callback hells?
What is Callback?
What's the event loop?
What is a blocking code?
How Node prevents blocking code?
What is Event Loop?
What is stream and what are types of streams available in Node.js?
What is Event Emmitter?
How to avoid callback hell in Node.js?
What is purpose of Buffer class in Node?
When should I use EventEmitter?
What is difference between synchronous and asynchronous method of fs module?
What are streams?
What is the preferred method of resolving unhandled exceptions in Node.js?
When should we use Node.js?
How to use Buffer in Node.js?
What is Chaining in Node?
What are the global objects of Node.js?
Explain how does Node.js work?
How does Node.js handle child threads?
How can you listen on port 80 with Node?
When to not use Node.js?
Is Node.js entirely based on a single-thread?
Does Node.js support multi-core platforms? And is it capable of utilizing all the cores?
Why to use Buffers instead of binary strings to handle binary data ?
What's a stub? Name a use case.
What tools can be used to assure consistent code style?
How to gracefully Shutdown Node.js Server?

⎇ FAQGURU/FAQGURU · MIT ↗

React50 questions

What is the use of refs?
What is JEST?
What are the advantages of ReactJS?
How to write comments in ReactJS?
What is context?
What is virtual DOM?
How does React work?
What is React?
What is props in ReactJS?
What are the major features of ReactJS?
What is ReactJS?
What are props in React?
How would you write an inline style in React?
What are the limitations of ReactJS?
What’s the difference between an "Element" and a "Component" in React?
What are stateful components?
What are stateless components?
What are portals in ReactJS?
What are fragments?
Why is it necessary to capitalize the components?
What is reconciliation?
What is the purpose of using super constructor with props argument?
When to use a Class Component over a Functional Component?
What are the advantages of using React?
What are Higher-Order components?
What are controlled components?
What is the difference between a Presentational component and a Container component?
How to create refs?
What are the differences between a class component and functional component?
What do you like about React?
What is inline conditional expressions?
What is the difference between state and props?
How is React different from AngularJS (1.x)?
What happens during the lifecycle of a React component?
How to pass a parameter to an event handler or callback?
What is the purpose of callback function as an argument of setState?
What is the difference between component and container in react Redux?
What is state in ReactJS?
How to create components in ReactJS?
What is the difference between Element and Component?
What are refs used for in React?
When rendering a list what is a key and what is it's purpose?
What is JSX?
Where in a React component should you make an AJAX request?
What is the difference between React Native and React?
Describe how events are handled in React.
What is Flux?
Where is the state kept in a React + Redux application?
What is the point of Redux?
What is Flow?

⎇ FAQGURU/FAQGURU · MIT ↗

SQL50 questions

What is PRIMARY KEY?
Define a temp table
What is a view?
What’s the difference between a local temp table and a global temp table?
What is blocking?
What is the difference between WHERE clause and HAVING clause?
What is FOREIGN KEY?
What is Normalization?
How can a column with a default value be added to an existing table?
What is DEFAULT?
What is the difference between inner and outer join?
Discuss INNER JOIN ON vs WHERE clause
What are the difference between clustered and a non-clustered index?
How do I perform an IF…THEN in an SQL SELECT?
Finding duplicate values in a SQL table
How does a hash table index work?
What are the advantages of using Stored Procedures?
What is Denormalization?
How to select first 5 records from a table?
Define ACID Properties
How a database index can help performance?
What is the difference between UNION and UNION ALL?
What is a cursor how does it work?
How do I UPDATE from a SELECT in SQL Server?
What is the difference between “INNER JOIN” and “OUTER JOIN”?
Is table size reduced, when you delete data from the table?
Explain Function vs. Stored Procedure in SQL Server
What are row constructors?
What is the difference between JOIN and UNION?
What is collation?
Describe the difference between truncate and delete
How does B-trees index work?
What are statistics?
How deadlock is resolved?
What is the difference among UNION, MINUS and INTERSECT?
What is a filegroup?
How can I do an UPDATE statement with JOIN in SQL?
How does truncate and delete operation effect Identity?
Explain a usage difference between user defined functions and stored procedures
What is a linked server?
How can we transpose a table using SQL (changing rows to column or vice-versa) ?
What would happen without an index?
Name types of Triggers
What are DMV's and DMF's?
What's the difference between a primary key and a unique key?
Delete duplicate values in a SQL table
What is the cost of having a database index?
How to generate row number in SQL Without ROWNUM
Explain the difference between exclusive lock and update lock
Insert results of a stored procedure into a temporary table

⎇ FAQGURU/FAQGURU · MIT ↗

AWS44 questions

What is AWS?
Explain the key components of AWS?
What is buckets in AWS?
What is AWS Cloudfront?
What do you mean by AMI? What does it include?
How can I download a file from EC2?
Is it possible to clone a EC2 instance data?
What is AWS Data Pipeline?
Explain the features of Amazon EC2 services
What is the connection between AMI and Instance?
Are S3 buckets region specific?
What is AWS Direct Connect?
What is AWS EBS?
What is AWS Lambda?
What is AWS DynamoDB?
What is AWS EMR?
Is data stored in S3 is always encrypted?
Can we attach single EBS to multiple EC2s same time?
What is AWS API gateway?
What are the security best practices for Amazon EC2 instances?
Can I automatically start and terminate my Amazon instance using Amazon API?
Can we still continue working on EBS while creating snapshot of it?
What is AWS Auto Scaling?
What is AWS Auto Scaling group?
What is the maximum size of a single S3 object?
What is AWS bucket policy?
Does AWS has the option for vertical "auto" scaling of EC2 instance?
What is AWS WAF? What are the potential benefits of using WAF?
How to get the instance id from within an EC2 instance?
What is AWS Cloudwatch?
What is the difference between Amazon EC2 and AWS Elastic Beanstalk?
How many storage options are there for EC2 Instance?
What is AWS Route 53?
How would you implement vertical auto scaling of EC2 instance?
What is Amazon Kinesis?
How to find a region from within an EC2 instance?
Where are EC2 snapshots stored?
When should one use the following: Amazon EC2, Google App Engine, Microsoft Azure and Salesforce.com?
When to use Amazon CloudFront and when S3?
Our EC2 micro instance occasionally runs out of memory. Other than using a larger instance size, what else can be done?
What is difference between Lightsail and EC2?
What is the underlying hypervisor for EC2?
How to safely upgrade an Amazon EC2 instance from t1.micro to large?
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CSS39 questions

Explain the three main ways to apply CSS styles to a web page
What is CSS?
What is DOM (Document Object Model) and how is it linked to CSS?
Explain the CSS “box model” and the layout components that it consists of
What is a CSS rule?
What existing CSS frameworks have you used locally, or in production? How would you change/improve them?
Have you played around with the new CSS Flexbox or Grid specs?
What is the difference between classes and IDs in CSS?
Describe floats and how they work
Explain CSS sprites, and how you would implement them on a page or site.
How would you approach fixing browser-specific styling issues?
What is CSS preprocessor and why to user one?
Have you ever worked with retina graphics? If so, when and what techniques did you use?
How is responsive design different from adaptive design?
How to create a zebra striped table with CSS?
What’s the difference between “resetting” and “normalizing” CSS? Which would you choose, and why?
How does CSS actually work (under the hood of browser)?
Explain your understanding of the box model and how you would tell the browser in CSS to render your layout in different box models.
What is CSS selectors? Name some.
Explain the usage of "table-layout" property
Describe pseudo-elements and discuss what they are used for.
What does Accessibility (a11y) mean?
What are the advantages/disadvantages of using CSS preprocessors?
What is a Grid System in CSS?
What's the difference between a `relative`, `fixed`, `absolute` and `static`ally positioned element?
Explain the purpose of clearing floats in CSS
How do you optimize your webpages for print?
Have you ever used a grid system, and if so, what do you prefer?
What are the different ways to visually hide content (and make it available only for screen readers)?
Describe z-index and how a stacking context is formed
What does * { box-sizing: border-box; } do? What are its advantages?
Can you explain the difference between coding a website to be responsive versus using a mobile-first strategy?
Explain the basic rules of CSS Specificity
Is there any reason you'd want to use `translate()` instead of `absolute` positioning, or vice-versa? And why?
What the code fragment has the greater CSS specificity?
What clearfix methods do you know? Provide some examples.
How to style every element which has an adjacent item right before it?
Write down a selector that will match any links end in .zip, .ZIP, .Zip etc...
[↑] Back to top

⎇ FAQGURU/FAQGURU · MIT ↗

Redux31 questions

What is Flux?
What is Redux DevTools?
What is Redux?
Do you need to keepIs all component states in Redux store?
How to add multiple middlewares to Redux?
What are Redux selectors and Why to use them?
What are the features of Redux DevTools?
What are reducers in redux?
What is Redux Thunk?
What is the difference between React context and React redux?
What is redux-saga?
What are the core principles of Redux?
How to set initial state in Redux?
How to structure Redux top level directories?
What are the downsides of Redux over Flux?
What are the differences between redux-saga and redux-thunk?
What is the purpose of the constants in Redux?
How to use connect from react redux?
Are there any similarities between Redux and RxJS?
What is Redux form?
What are the main features of Redux Form?
How to access redux store outside a react component?
What is the proper way to access Redux store?
What are the differences between call and put in redux-saga?
Whats the purpose of at (@) symbol in the redux connect decorator?
How to make Ajax request in Redux?
Why are Redux state functions called as reducers?
How to reset state in redux?
What is the mental model of redux-saga?
How Relay is different from Redux?
[↑] Back to top

⎇ FAQGURU/FAQGURU · MIT ↗

GraphQL14 questions

What is GraphQL?
Is GraphQL a Database Technology?
Is GraphQL only for React / Javascript Developers?
How to do Error Handling?
Where is GraphQL useful?
What is GraphQL schema?
How to do Authentication and Authorization?
Does GraphQL Support Offline Usage?
How to do Server-side Caching?
List the key concepts of the GraphQL query language
Explain the main difference between REST and GraphQL
What kind of operations could GraphQL schema have?
Are there any disadvantages to GraphQL?
[↑] Back to top

⎇ FAQGURU/FAQGURU · MIT ↗