I recently interviewed at Meta for an E4 Infra SWE and was unfortunately rejected :(. This community has been invaluable for me so this is my interview experience to give back.

My preparation:

I knew the Meta interview was intense so my interview preparation was thorough. This included

• Completing the top 100 most frequent Leetcode Meta tagged questions from 6 months
• Going over the most common infra system design problems from Hello Interview (will expand on this later)
• Coming up with answers in STAR format for the most common behavioral interview questions

The interviews:

Meta mock phone screen:

• Asked two questions directly from the top 50 LC-tagged
  • First question: Array Partitioning
  • Second question: Array Sum
• I solved the first question but stumbled on the second because I wasn't confident in my solution. I kept proposing different approaches until the interviewer asked if I was sure about my current solution. I initially thought this was a hint, but later realized my solution was correct and communicated that to which the interviewer agreed.
  • Takeaway here is that not every comment from the interviewer is a hint. Study the questions thoroughly to avoid these pitfalls

Meta phone screen:

• Another standard phone screen being asked two questions directly off of top 50 LC tagged
  • First question: Array Sum
  • Second question: Tree BFS
• Aced both questions
• I was notified the next day I had made it to the onsite

Preparing for onsite:

Preparing for the onsite was hectic not only because of LC/Behavioral prep but also because this would be my first system design interview. I had to spend a considerable amount of time learning the fundamentals before tackling the common Meta system design problems from Hello Interview

Regarding Hello Interview, I was impressed with the service. Why?

• It's no secret that most people want to learn system design to pass interviews, and they organize their content in a way that exactly explains what's expected of each level and how system design interviews are administered/graded
• Their mock interview service simulates a real interview and they grade you + provide feedback which is extremely valuable for improving
• While the price is not cheap, I was willing to pay to receive coaching from qualified experts (I cannot say the same for many other interview services)
• My only feedback is that my Meta mock interviewer had much more experience with product design than system design which is something I'm not sure they take into account when assigning interviewers

For the Meta onsite interviews

Meta onsite 1 (coding)

• This round tripped me up and I was disappointed given how much I had prepared
  • First question: Tree BFS (was able to get optimal runtime but not optimal space)
  • Second question: Multiple binary searches on an array (did not get the optimal solution)
• Immediately after the interview, I realized the mistake I made on both questions but could not go back and change it :(
• I struggled with the second question in particular since it was unlike most of the other Meta tagged question

Meta onsite 2 (behavioral)

• Not much to say about this round. None of the questions were a surprise and I answered them to the best of my capacity stressing my ability to work with other people specifically

Meta onsite 3 (system design)

• This round was mixed. I couldn't understand the interviewer too well but I didn't want to keep asking questions and look like I was fishing for answers
• I ended up reciting all of the system design knowledge related to the answer and hoped for the best. There wasn't much discussion overall but I felt like my points were valid/somewhat correct

Meta onsite 4 (coding)

• This was my strongest performance and I was proud of myself after this round. I solved both questions optimally
  • First question: Number Verification (think LC hard)
  • Second question: Tree BFS

The recruiter called the day after my final onsite and while I braced myself for a rejection, I was surprised to know that HC was on the fence and they wanted to give me a follow-up coding round (looks like my other rounds were not that bad)

Meta onsite 5 (follow-up coding)

• I fumbled this round and this was especially brutal/heartbreaking considering how close I had made it.
  • First question: Palindrome (think LC hard)
  • Grid DFS
• I was not able to get the first question (I should have) and while I did solve the second question I needed a hint or two to fully understand the problem.

The recruiter notified me the same day after the follow-up coding round that I was rejected

This was an eye-opening experience overall and I know I have a lot more work to do if I want to make sure I pass next time around.