Meta Senior Software Engineer Interview Experience — Passed a Four-Round AI-Enabled Onsite, Team Match Still in Limbo

Position: Software Engineer, Product
Result: Target E5 Pass

The OA was pretty old at this point, but the questions are in the forum's question bank. The recruiter waived my phone screen and put me straight into the onsite. The onsite was 4 rounds total.

AI-Enabled System Design
Billed as "AI-Enabled," but the interviewer seemed to be doing this format for the first time — his question bank wasn't really ready either, and even setting up the environment took about 10 minutes. In the end he gave me a design DoorDash question, with the focus mainly on decision trade-offs — things like shopping cart persistence, driver location updates, etc.

AI-Native BQ
Pretty standard BQ questions — proudest project, resolving conflict, that kind of thing. At the end he asked about my experience using AI.

AI-Enabled Coding 1
The classic Maze Solver. The first three parts were debugging, and the last part was keys and doors.

AI-Enabled Coding 2
The interviewer added his own little twist and called it "ParanoidEcho," but underneath it's really the word container problem — an open-ended question mainly testing how you drive decisions. They gave a brute-force implementation and asked how I'd optimize it. I identified the bottleneck first, then brainstormed with AI (I wasn't totally sure if that was the right moment to use AI, but it seemed to work out). AI gave me two options, Trie and Hashset — I walked through the pros and cons of each, decided to implement Trie first, then immediately had AI implement it. Once the tests passed, the interviewer had me plug the implementation into the benchmark (which was provided). After that ran, he had me write the other solution too and benchmark it — the runtime came out about the same, but it used more memory. He had two benchmarks prepared, and after running both he did a quick, fairly casual analysis and wrapped up the interview.

I interviewed on a Wednesday and got the notification that I passed the following Monday. But it landed right in the middle of Meta's layoff news, so team matching might take forever...