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Interview questions from top companies, mapped to the exact round they show up in. Prep for what you will actually face.

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Online AssessmentDSA / CodingMachine CodingLow-Level Design

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The Loop aggregates publicly shared interview experiences and curated commonly-asked questions, each labeled with its source. Not affiliated with any company listed.

CC BY-NC 4.0 · © 2026

← Barclays

Senior Frontend at Barclays

FrontendSeniorOffer◆ Commonly asked· 2023

A senior frontend loop. Fast-paced; expect follow-ups that push on depth.

The loop · 6 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Merge k sorted lists.
    SeniorHard◆ Commonly asked
    #heap#linked-list
    PracticeLeetCode↗GeeksforGeeks↗
  • Reverse nodes in k-group.
    SeniorHard◆ Commonly asked
    #linked-list
    PracticeLeetCode↗GeeksforGeeks↗
  • Maximum depth of a binary tree.
    SeniorEasy◆ Commonly asked
    #tree#dfs
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Build a modal/dialog with focus trapping.
    SeniorMedium◆ Commonly asked
    #react#a11y
    PracticeGeeksforGeeks↗Search↗
  • Build a multi-step form with validation.
    SeniorMedium◆ Commonly asked
    #react#forms
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design a search autocomplete at Google scale.
    SeniorHard◆ Commonly asked
    #trie#ranking#cache
    PracticeGeeksforGeeks↗Search↗
  • Design an image-heavy gallery with lazy loading and a CDN.
    SeniorMedium◆ Commonly asked
    #frontend#perf#cdn
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • Difference between CSS Grid and Flexbox — when to use each.
    SeniorEasy◆ Commonly asked
    #css#layout
    PracticeGeeksforGeeks↗Search↗
  • What are React keys and why do they matter?
    SeniorEasy◆ Commonly asked
    #react
    PracticeGeeksforGeeks↗Search↗
  • What is the virtual DOM and why does it help?
    SeniorMedium◆ Commonly asked
    #react
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

Scope, ownership, and role-fit discussion with the manager.

  • Tell me about a technical bet that did not pay off.
    Senior◆ Commonly asked
    #risk#judgment
06

Round 06 · 2 questions

Behavioral / HR

Values, collaboration, and past-experience (STAR) questions.

  • Describe mentoring or unblocking another engineer.
    Senior◆ Commonly asked
    #mentorship#star
  • Tell me about a time you went above and beyond for a customer.
    Senior◆ Commonly asked
    #customer#star

Practice each round across every company

  • DSA / Coding
  • Machine Coding
  • System Design
  • Tech Deep-Dive
  • Hiring Manager
  • Behavioral / HR

◆ This experience is composed from commonly reported questions for this role and level. Real, individually-shared interviews will be layered in over time.