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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

← Kraken

Senior Backend at Kraken

BackendSeniorOffer◆ Commonly asked· 2025

6-round senior backend process. Pragmatic questions — more real-world than pure puzzles.

The loop · 6 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • Search in a rotated sorted array.
    SeniorMedium◆ Commonly asked
    #binary-search
    PracticeLeetCode↗GeeksforGeeks↗
  • Combination sum.
    SeniorMedium◆ Commonly asked
    #backtracking
    PracticeLeetCode↗GeeksforGeeks↗
  • Minimum window substring.
    SeniorHard◆ Commonly asked
    #sliding-window#string
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Build a REST endpoint with pagination, filtering and sorting.
    SeniorMedium◆ Commonly asked
    #api#pagination
    PracticeGeeksforGeeks↗Search↗
  • Build an in-memory pub/sub with topic subscriptions.
    SeniorMedium◆ Commonly asked
    #pub-sub
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design a notification system (push/email/SMS).
    SeniorMedium◆ Commonly asked
    #queues#fanout
    PracticeGeeksforGeeks↗Search↗
  • Design an object storage service like S3.
    SeniorHard◆ Commonly asked
    #storage#scale
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • How do you design a public API for backward compatibility?
    SeniorMedium◆ Commonly asked
    #api-design
    PracticeGeeksforGeeks↗Search↗
  • How does a load balancer choose a backend?
    SeniorMedium◆ Commonly asked
    #networking
    PracticeGeeksforGeeks↗Search↗
  • Explain database replication lag and how to mitigate it.
    SeniorMedium◆ Commonly asked
    #databases#replication
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

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

  • Walk me through a technical trade-off you regret.
    Senior◆ Commonly asked
    #judgment
06

Round 06 · 2 questions

Behavioral / HR

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

  • Describe a disagreement on a code review and how it ended.
    Senior◆ Commonly asked
    #conflict#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.