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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

← Riot Games

Senior Backend at Riot Games

BackendSeniorNo offer◆ Commonly asked· 2024

A senior backend loop. Balanced across coding, design, and collaboration.

The loop · 6 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Set matrix zeroes.
    SeniorMedium◆ Commonly asked
    #matrix
    PracticeLeetCode↗GeeksforGeeks↗
  • Contains duplicate.
    SeniorEasy◆ Commonly asked
    #array#hashmap
    PracticeLeetCode↗GeeksforGeeks↗
  • Diameter 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.

  • Implement a job queue with retries and backoff.
    SeniorHard◆ Commonly asked
    #queue#reliability
    PracticeGeeksforGeeks↗Search↗
  • Implement an LRU + TTL cache library.
    SeniorHard◆ Commonly asked
    #cache#ttl
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design an analytics / metrics dashboard backend.
    SeniorHard◆ Commonly asked
    #time-series#aggregation
    PracticeGeeksforGeeks↗Search↗
  • Design a feature-flag service.
    SeniorMedium◆ Commonly asked
    #config#rollout
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • Explain JWT structure and common pitfalls.
    SeniorMedium◆ Commonly asked
    #auth#security
    PracticeGeeksforGeeks↗Search↗
  • Explain how DNS resolution works end to end.
    SeniorMedium◆ Commonly asked
    #networking
    PracticeGeeksforGeeks↗Search↗
  • How do you run a zero-downtime database migration?
    SeniorHard◆ Commonly asked
    #databases
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

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

  • How do you run an incident and the postmortem after?
    Senior◆ Commonly asked
    #reliability#process
06

Round 06 · 2 questions

Behavioral / HR

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

  • Tell me about a project you are most proud of.
    Senior◆ Commonly asked
    #star
  • Tell me about the hardest bug you have debugged.
    Senior◆ Commonly asked
    #debugging#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.