Scale Engineer

Software Engineer

Software EngineerL3Medium

The Software Engineer L3 interview at Jane Street is designed to assess a candidate's foundational knowledge in computer science, problem-solving abilities, and coding proficiency. It typically involves a mix of technical and behavioral questions to evaluate a candidate's fit for the role and the company culture.

Rounds·3

Timeline·~14d

Experience·1 - 3 yrs

Comp band·US$90000 - US$120000

Interview time·120 min

Evaluation

What they measure.

  • Problem-solving approach
  • Algorithmic thinking
  • Code clarity and correctness
  • Efficiency of the solution
  • Communication of thought process

Preparation

How to prepare.

Tips

  1. Review fundamental data structures (arrays, linked lists, trees, hash maps) and algorithms (sorting, searching, graph traversal).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium-difficulty problems.
  3. Brush up on your chosen programming language's syntax, standard library, and common idioms.
  4. Understand basic operating system concepts (processes, threads, memory management).
  5. Prepare to discuss your past projects and experiences in detail, highlighting your contributions and learnings.
  6. Research Jane Street's business and culture to understand their focus on quantitative trading and technology.
  7. Practice explaining your thought process out loud as you solve problems.

Study plan

Fig · Study plan — 04 phases

01 / 04
01

Phase 01 of 04

Data Structures

Weeks 1-2: Data Structures (Arrays, Lists, Trees, Hash Maps). Practice implementations.

Weeks 1-2: Focus on Data Structures. Deep dive into arrays, linked lists, stacks, queues, trees (binary trees, BSTs, heaps), and hash tables. Understand their time and space complexities for common operations. Practice implementing them from scratch.

Questions

Commonly asked.

  • Given an array of integers, find the contiguous subarray with the largest sum.
  • Implement a function to reverse a linked list.
  • Explain the time and space complexity of quicksort.
  • Describe a challenging technical problem you faced and how you solved it.
  • How would you design a URL shortener service?
  • What is polymorphism? Provide an example.
  • Write a function to find the kth smallest element in an unsorted array.

Locations

Regional differences.

Fig · Regions — 03 locations

01 / 03

Location

New York

Interview focus

Problem-solving skillsCoding efficiencyUnderstanding of core CS conceptsCommunication skills

Common questions

  • Explain the difference between a process and a thread.
  • Describe a situation where you had to debug a complex issue. How did you approach it?
  • What are your favorite data structures and why?
  • How would you design a system to handle real-time stock price updates?

Tips

  • For New York: Be prepared for questions related to financial markets and trading systems.
  • For Hong Kong: Expect questions that might touch upon Asian market specifics or high-frequency trading concepts.
  • For London: Familiarize yourself with European market structures and regulatory aspects if applicable.

Rounds

Round-by-round.

Expand a step for evaluation criteria, sample questions, and prep notes.

DSA

Coding questions at Jane Street.

Frequently reported on Jane Street loops

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