LinkedIn

Role: Senior Software Engineer Infrastructure

College: Not Specified

Interview Date: Late September 2025

Interview Type: Full-Time

Result: Rejected

Difficulty: Hard (Coding 1 due to interviewer), Medium (Coding 2, System Design, Host Manager)

Rounds: 4 rounds

Topics Asked: Algorithms (Variant of Repeated DNA Sequences, Topological Sort - Package Build Order), System Design (Job Scheduler - functional/non-functional requirements, tradeoffs), Behavioral (Standard questions, scenario-based problem-solving)

Experience:

The candidate completed their onsite loop in late September 2025 for a Senior Software Engineer Infrastructure role.

Coding 1
A variant of the "repeated DNA Sequences" problem (LeetCode Hard) was asked: find all 10-letter-long sequences that occur more than once in a DNA string and return them in ascending order. The interviewer's constant interruptions made explaining the approach difficult, but the candidate managed to code and dry run the solution.

Coding 2
The problem was "Package Build Order": given `Set getDependencies(Package packageName)`, implement `List getBuildOrder()`. This was a standard topological sort problem. The candidate wrote the solution and walked through it with examples, and this round went smoothly.

System Design
The task was to design a "Job Scheduler". The candidate covered all functional requirements (execute cron/adhoc jobs, monitor/cancel status) and non-functional requirements (highly available, scalable for 10k jobs/sec, execute at least once, retry failed jobs, low latency). All tradeoffs were discussed, and the interviewer expressed satisfaction.

Host Manager Round
This round involved standard behavioral questions, followed by a real-world scenario that the candidate had to solve. The candidate presented their approach, which the hiring manager approved, and was then asked for a timeline estimate (estimated 2 quarters, but LinkedIn reportedly took 5 years to implement it, which might have been a trick question).

The overall result for this candidate was a rejection.