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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

← Millennium

Staff+ Backend at Millennium

BackendStaff+Rejected◆ Commonly asked· 2023

Staff backend interview. 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.

  • Minimum window substring.
    Staff+Hard◆ Commonly asked
    #sliding-window#string
    PracticeLeetCode↗GeeksforGeeks↗
  • Coin change — fewest coins to make an amount.
    Staff+Medium◆ Commonly asked
    #dp
    PracticeLeetCode↗GeeksforGeeks↗
  • Implement a trie (prefix tree).
    Staff+Medium◆ Commonly asked
    #trie
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 1 question

Low-Level Design

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

  • Design a hotel-reservation system core.
    Staff+Medium◆ Commonly asked
    #oop#concurrency
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design a distributed key-value store.
    Staff+Hard◆ Commonly asked
    #replication#consistency
    PracticeGeeksforGeeks↗Search↗
  • Design a multi-tenant SaaS data model.
    Staff+Hard◆ Commonly asked
    #multi-tenancy#databases
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 1 question

Hiring Manager

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

  • How do you keep a team unblocked and shipping?
    Staff+◆ Commonly asked
    #leadership
05

Round 05 · 2 questions

Behavioral / HR

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

  • Describe something you shipped that you were not proud of.
    Staff+◆ Commonly asked
    #tradeoffs#star
  • Tell me about a time you simplified something overly complex.
    Staff+◆ Commonly asked
    #judgment#star

Practice each round across every company

  • DSA / Coding
  • Low-Level Design
  • System Design
  • 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.