Confluent

Role: SDE (Software Development Engineer)

College: Not Specified

Interview Date: October 2024

Interview Type: On-Campus, Full-Time

Result: Waitlisted

Difficulty: Hard

Rounds: 3 rounds (plus an initial Online Coding Round)

Topics Asked: Data Structures, Algorithms, Concurrency, System Design, Behavioral

Experience:

The interview process for the SDE role consisted of an initial online coding round followed by three virtual interview rounds.

Round 0: Online Coding Round (OA)
This round had three coding questions. The candidate successfully solved one question and partially solved the other two. Out of 13 students, 8 advanced to the interview stage.

Round 1: DSA Question (45 minutes)
A single Leetcode hard DSA question was presented: "Number of Atoms". The candidate successfully solved the question, performed dry-run test cases, and discussed the approach with the interviewer, receiving suggestions for improvement.

Round 2: Concurrency Round (1 hour)
After an introduction, the candidate was asked to implement a thread-safe LRU cache. The proposed solution involved `put`, `get`, and `size` functions, emphasizing that no two functions could be accessed simultaneously by different threads. Initially, a "turn" variable was suggested, but after interviewer feedback regarding multiple accesses to the `size` function, the solution was revised to include "turn" and "turn_size" variables. The interviewer then brought up thread starvation, leading to the incorporation of a semaphore. Discussions also included the Reader-Writer problem and its solutions.

Round 3: HR Round
This round involved general behavioral questions about strengths, weaknesses, something to be proud of, and something not to be proud of.

Overall Experience: Only one student secured the role, and the candidate was placed on the waitlist.