My FanCode Interview Experience

Let me walk you through my interview experience at FanCode — what the rounds looked like, what I prepared, and what I'd tell myself if I could go back.

How I found the role

A college senior mentioned that FanCode was hiring backend interns. I'd been working on systems-level projects and wanted to see what production infrastructure looked like at scale — thousands of concurrent users hitting APIs during live cricket matches.

Round 1: Online Assessment

Standard setup. Two problems, 90 minutes. The first was an array manipulation problem — medium difficulty, required sliding window. The second was a graph problem that needed BFS with some state tracking. I solved both but spent too long optimizing the first one.

Lesson: solve correctly first, optimize only if time permits.

Round 2: Technical Interview

60-minute video call with a senior engineer. Three parts:

Data structures: implement an LRU cache from scratch. I used a doubly-linked list with a hash map. The interviewer wanted clean code more than clever tricks.

System design: design a notification system for live sports scores. We talked about pub/sub, message queues, fan-out strategies. I drew on what I knew about Kafka from my own reading.

Project deep-dive: PacketScope got the most questions. Having a real project to talk about — not just a tutorial clone — made this the strongest part of my interview.

Round 3: System Design Deep Dive

We designed a live scorecard system — how to ingest data from multiple sources, handle conflicting updates, serve it to millions of users with minimal latency. The interesting part was the edge cases: what happens when two data sources disagree on a score?

What I'd do differently

Practice more system design. Reading DDIA before the interview would have helped enormously. Also: prepare specific stories about your projects — not "I built X with Y" but "I was trying to solve Z, tried A which didn't work because of B, then tried C and learned D."

The outcome

I got the offer. If you're a student reading this — build things, write about them, and interview at places that excite you. The preparation matters less than the curiosity.