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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

← Mixpanel

Mid Backend at Mixpanel

BackendMidWithdrew◆ Commonly asked· 2025

5-round mid backend process. Balanced across coding, design, and collaboration.

The loop · 5 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Contains duplicate.
    MidEasy◆ Commonly asked
    #array#hashmap
    PracticeLeetCode↗GeeksforGeeks↗
  • Group anagrams from a list of strings.
    MidMedium◆ Commonly asked
    #hashmap#string
    PracticeLeetCode↗GeeksforGeeks↗
  • Coin change — fewest coins to make an amount.
    MidMedium◆ Commonly asked
    #dp
    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.
    MidHard◆ Commonly asked
    #queue#reliability
    PracticeGeeksforGeeks↗Search↗
  • Implement cursor-based pagination over a sorted dataset.
    MidMedium◆ Commonly asked
    #pagination#api
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 1 question

Low-Level Design

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

  • Design a library management system.
    MidMedium◆ Commonly asked
    #oop
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • What is backpressure and how do you handle it?
    MidHard◆ Commonly asked
    #streaming#reliability
    PracticeGeeksforGeeks↗Search↗
  • Explain leader election and consensus (Raft) at a high level.
    MidHard◆ Commonly asked
    #distributed#consensus
    PracticeGeeksforGeeks↗Search↗
  • Explain connection pooling and why it matters.
    MidMedium◆ Commonly asked
    #databases
    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 a project you are most proud of.
    Mid◆ Commonly asked
    #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.