Facebook E5 London Offer

I had an interview for an E5 Lead Engineer position at Facebook in London. My experience level was 12 years.

Talk with the recruiter (30 mins):

This discussion was crucial for setting my expectations and understanding the interview process. The recruiter provided valuable insights and resources for preparation. I treated this as an interview itself, asking all my questions about the preparation process.

Technical Phone Screen (45 mins):

I was asked two coding questions in this round. Both were relatively easy, and the key was to articulate my thought process clearly. I made sure to test my code immediately after writing it, which impressed the interviewer.

Virtual Onsite (4 rounds):

Behavioral (45 mins):

This round focused on my past experiences in teams and how I handled technical challenges. The questions were open-ended, and each answer led to follow-up questions. I wasn't asked any coding questions in this round. My recruiter had mentioned that a strong positive signal in this round is critical, as a negative signal here can lead to a 'no-hire' decision even with strong technical performance.

System/Product Design (45 mins):

I was tasked with designing a file-sharing system similar to Dropbox. During requirement gathering, I pointed out a potential security issue with auto-sync, which seemed to impress the interviewer. My proposal for staggered scale-up based on usage trends also received positive feedback. I drove the discussion, answering clarification questions and providing high-level differences between SQL and NoSQL without getting bogged down in details.

Coding 1 (45 mins):

This round was similar to the phone screen but with a higher bar. I tackled two coding problems. The first involved a LeetCode problem, where I used Breadth-First Traversal and discussed follow-up questions on parallelization and memory constraints. The second was another LeetCode problem, which I solved very quickly.

Coding 2 (45 mins):

I faced two more coding questions here. For the first, which involved checking interval coverage, I initially missed a boundary case but caught and fixed it during testing without prompting, which was viewed positively. For the second, finding connected sub-graphs in an undirected graph, I used Depth-First Traversal. I ran out of time to complete the code, but because I had modularized my solution, I could clearly outline the remaining implementation details for the interviewer.

The next day, I received positive feedback from my recruiter for all four rounds and was informed that I would proceed to the review board. The offer came through the day after that.