Meta E6 London - Software Engineer (Product) - Full Loop

I recently completed the full-loop interview with Meta for the E6 level and wanted to share my experience with the LC community.

Screening Round
1. Subtree of Another Tree — Solved it correctly.
2. Insert intervals variant — Shared the algorithm to solve it, but couldn’t complete the full solution due to time limits. The interviewer seemed somewhat satisfied with my approach.

Coding Round 1
1. Variant of Basic Calculator II — Solved it using a stack and covered all edge cases. It could be solved using string split as well, but the stack solution looked cleaner to me.
2. Minimum Add to Make Parentheses Valid — I started with a stack-based solution, wrote the complete code, and covered edge cases. The interviewer asked me to optimize it, but I couldn’t think of the two-pointers greedy approach within the time limit.

Coding Round 2
1. Closest Binary Search Tree Value — Solved well with proper dry run and edge cases.
2. Variant of Random Pick with Weight — Took a few hints from the interviewer for this question and finally solved it with proper edge cases.

Behavioral Round
1. Tell me about a high-impact project with an aggressive deadline.
2. Have you ever had a conflict with a colleague?
3. Tell me about a time you influenced without formal authority.
4. Describe a time you took ownership beyond your scope.
5. Did you ever fail? What did you learn from it?
6. Did you receive any feedback from your manager, and how did you act on it?
7. Did you face any challenges handling cross-team requirements?
8. How have you helped your peers or juniors grow?
9. How did you convince your leads/managers to optimize a specific flow/process?
10. Additional follow-ups on these questions.

I felt I did well in this round, answering using the STAR pattern.

Product Architecture 1
1. Design Spotify —
I feel I could have done better here. I didn’t handle the deep dives and follow-ups well. I had a hectic day at the office, but that’s just an excuse.

Product Architecture 2
1. Design Dropbox —
I think I nailed this one. The interviewer was excellent.

Result
All the interviewers were really good, and I had a great learning experience. I prepared for only 3 weeks, focusing mostly on coding. For system design, I only prepared for a single day, which wasn’t sufficient. I heard from my recruiter that the feedback wasn’t positive, at least not for the level they were hiring for. I’ll be receiving detailed feedback next week.

I’ll work on the gaps, improve, and come back stronger.