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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.

MIT · © 2026

← Roblox

Mid Backend at Roblox

BackendMidNo offer◆ Commonly asked· 2025

A mid backend loop. Pragmatic questions — more real-world than pure puzzles.

The loop · 5 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Sliding window maximum.
    MidHard◆ Commonly asked
    #deque#sliding-window
    PracticeLeetCode↗GeeksforGeeks↗
  • Trapping rain water.
    MidHard◆ Commonly asked
    #two-pointers#array
    PracticeLeetCode↗GeeksforGeeks↗
  • Median of two sorted arrays.
    MidHard◆ Commonly asked
    #binary-search
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Implement an idempotent "charge" endpoint.
    MidHard◆ Commonly asked
    #idempotency#payments
    PracticeGeeksforGeeks↗Search↗
  • Build a key-value store with TTL expiry.
    MidMedium◆ Commonly asked
    #cache#ttl
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 1 question

Low-Level Design

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

  • Design classes for a parking lot.
    MidMedium◆ Commonly asked
    #oop#design-patterns
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • Explain how you handle concurrency / race conditions.
    MidHard◆ Commonly asked
    #concurrency
    PracticeGeeksforGeeks↗Search↗
  • SQL vs NoSQL — how do you choose for a given workload?
    MidMedium◆ Commonly asked
    #databases
    PracticeGeeksforGeeks↗Search↗
  • How do you prevent and detect N+1 queries?
    MidMedium◆ Commonly asked
    #databases#orm
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 2 questions

Behavioral / HR

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

  • Describe something you shipped that you were not proud of.
    Mid◆ Commonly asked
    #tradeoffs#star
  • Tell me about a project you are most proud of.
    Mid◆ Commonly asked
    #star

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