Janestreet Interview Questions (3+ Questions)
Last Updated: June 8, 2026 • 3 Questions • Real Company Interviews
Prepare for your Janestreet interview with our comprehensive collection of 3+ real interview questions and detailed answers. These questions have been curated from actual Janestreet technical interviews across various roles including DevOps Engineer, Data Engineer, QA Engineer, and more.
Table of Contents
- Handle Disk Leak in Docker (medium) 🔒
- Find Highest Salary (easy) 🔒
- Car Fleet (medium)
Our Janestreet interview questions cover a wide range of technical topics and difficulty levels, from entry-level positions to senior roles. Each question includes detailed explanations and answers to help you understand the concepts and prepare effectively for your interview.
💡 Pro Tips for Janestreet Interviews
- Practice each question and understand the underlying concepts
- Review Janestreet's specific technologies and methodologies
- Prepare follow-up questions and edge cases
- Practice explaining your solutions clearly and concisely
Interview Questions & Answers
1. Handle Disk Leak in Docker
Diagnose phantom disk usage caused by deleted files still held open by running processes. Use lsof to find deleted file handles, inspect /proc/PID/fd/ for broken symlinks, identify processes preventing space reclamation, and create cleanup scripts to close or restart offending processes. Essential for container storage management, preventing disk exhaustion, application log rotation failures, and long-running container maintenance.
2. Find Highest Salary
Objective
Write an SQL query to retrieve the names and salaries of the highest-paid employee(s) from the employees table.
Additional Information
- The
employeestable consists of the following columns:id(integer): The unique identifier for each employee.name(string): The...
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3. Car Fleet
def car_fleet(target: int, position: list[int], speed: list[int]) -> int:
pair = [[p, s] for p, s in zip(position, speed)]
stack = []
# Sort by position (reverse) to process closest to target first
for p, s in sorted(pair)[::-1]:
stack.append((target - p) / s)
if len(stack) >= 2 and stack[-1] <= stack[-2]:
stack.pop()
return len(stack)
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