Jane Street | Data Engineer | Hongkong | Rejected
- Location
- Hongkong
- Experience
- 2.1 years
- Posted
- 27 Mar 2026
Summary
I was asked to solve a problem about flagging users with exactly k consecutive login failures; although I eventually fixed an edge case and solved it, I was rejected.
How it went
**Status:** 2.10 YOE **Position:** Data Engineer **Location:** Hongkong
Round 1: Problem Solving
- Question: Given a list of users and their login events (Success or Fail), flag users who have failed consecutively for exactly
ktimes. Conceptually similar to Max Consecutive Ones but with string events and tracking user IDs: https://leetcode.com/problems/max-consecutive-ones/
Verdict: I initially missed an edge case but was able to debug and solve it during the interview. However, I was rejected. Jane Street has an extremely high bar, and I assume they were looking for a completely flawless first-pass execution.
Questions asked (1)
- 01
Flag users with exactly k consecutive login failures
Data Structures & Algorithms
Open the problemGiven a list of users and their login events (Success or Fail), flag users who have failed consecutively for exactly
ktimes. This is conceptually similar to the LeetCode "Max Consecutive Ones" problem but applied to string events per user.