theloop
CompaniesRoundsQuestionsSearchProgress
theloop

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

View source

Browse

CompaniesSearchAll rounds

Rounds

Online AssessmentDSA / CodingMachine CodingLow-Level Design

Contribute

Share an interviewReport an issueStar on GitHub

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

← Qualys

Mid Backend at Qualys

BackendMidWithdrew◆ Commonly asked· 2024

5-round mid backend process. Fundamentals mattered as much as getting to an answer.

The loop · 5 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Pacific Atlantic water flow.
    MidMedium◆ Commonly asked
    #dfs#grid
    PracticeLeetCode↗GeeksforGeeks↗
  • Top K frequent elements.
    MidMedium◆ Commonly asked
    #heap#hashmap
    PracticeLeetCode↗GeeksforGeeks↗
  • Reverse nodes in k-group.
    MidHard◆ Commonly asked
    #linked-list
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Implement a leaderboard API backed by a sorted set.
    MidMedium◆ Commonly asked
    #redis#ranking
    PracticeGeeksforGeeks↗Search↗
  • Design and build a URL-shortener service (API + storage).
    MidMedium◆ Commonly asked
    #api#hashing
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 1 question

Low-Level Design

Object-oriented / low-level design of a focused module.

  • Design a movie-ticket booking system (BookMyShow).
    MidHard◆ Commonly asked
    #oop#concurrency
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • How does the OAuth 2.0 authorization-code flow work?
    MidMedium◆ Commonly asked
    #auth#security
    PracticeGeeksforGeeks↗Search↗
  • How does a write-ahead log guarantee durability?
    MidHard◆ Commonly asked
    #databases
    PracticeGeeksforGeeks↗Search↗
  • What is a deadlock and how do you avoid one?
    MidHard◆ Commonly asked
    #concurrency
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 2 questions

Behavioral / HR

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

  • Why this company, and why this role?
    Mid◆ Commonly asked
    #motivation
  • Tell me about receiving hard feedback and acting on it.
    Mid◆ Commonly asked
    #feedback#star

Practice each round across every company

  • DSA / Coding
  • Machine Coding
  • Low-Level Design
  • Tech Deep-Dive
  • 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.