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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

← Jane Street

Senior Full-stack at Jane Street

Full-stackSeniorNo offer◆ Commonly asked· 2024

A senior fullstack loop. Coding-heavy early, design and behavioral later.

The loop · 6 rounds

01

Round 01 · 3 questions

DSA / Coding

Data structures & algorithms on a whiteboard or shared editor.

  • 3Sum.
    SeniorMedium◆ Commonly asked
    #two-pointers#array
    PracticeLeetCode↗GeeksforGeeks↗
  • Regular expression matching.
    SeniorHard◆ Commonly asked
    #dp#string
    PracticeLeetCode↗GeeksforGeeks↗
  • Jump game.
    SeniorMedium◆ Commonly asked
    #greedy#dp
    PracticeLeetCode↗GeeksforGeeks↗
02

Round 02 · 2 questions

Machine Coding

Build a working component or service under time pressure.

  • Build a star-rating component (controlled + accessible).
    SeniorEasy◆ Commonly asked
    #react#a11y
    PracticeGeeksforGeeks↗Search↗
  • Build a tic-tac-toe game with win detection.
    SeniorEasy◆ Commonly asked
    #react#state
    PracticeGeeksforGeeks↗Search↗
03

Round 03 · 2 questions

System Design

High-level architecture of a large-scale system.

  • Design a web crawler.
    SeniorHard◆ Commonly asked
    #queues#dedup#scale
    PracticeGeeksforGeeks↗Search↗
  • Design a distributed task queue like Celery.
    SeniorHard◆ Commonly asked
    #queues#workers
    PracticeGeeksforGeeks↗Search↗
04

Round 04 · 3 questions

Tech Deep-Dive

Deep questions on your core stack and fundamentals.

  • Explain optimistic vs pessimistic locking.
    SeniorHard◆ Commonly asked
    #databases
    PracticeGeeksforGeeks↗Search↗
  • What are Web Workers and when would you use one?
    SeniorMedium◆ Commonly asked
    #browser#perf
    PracticeGeeksforGeeks↗Search↗
  • Difference between controlled and uncontrolled inputs.
    SeniorEasy◆ Commonly asked
    #react#forms
    PracticeGeeksforGeeks↗Search↗
05

Round 05 · 1 question

Hiring Manager

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

  • How do you balance tech debt against feature work?
    Senior◆ Commonly asked
    #prioritization
06

Round 06 · 2 questions

Behavioral / HR

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

  • Describe a time you disagreed with a teammate. How did it resolve?
    Senior◆ Commonly asked
    #conflict#star
  • Describe something you shipped that you were not proud of.
    Senior◆ Commonly asked
    #tradeoffs#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.