Position - Backend Engineer
YOE - 5

Coding background: 2200+ rating on leetcode contests with consistent 4 solves in almost every contest. I knew my weakness would be communication, so I planned to explain every part of my thought process. I think I did not stop speaking for more than a period of 5 seconds in all of the interviews. Sadly, I did fumble on easy-medium questions. Solving a problem silently vs in front of an interviewer while explaining everything are two very different things.
System design background: I have 2 years of hands-on system design experience. However, after reading about the system design process and material shared by the recruiter, I was surprised how much detail(CPU, memory, bandwidth etc. bottlenecks) they expect during an interview. Did all of the questions on G-R-R-O-K-K-I-N-G except the one that was asked in the interview. (-_-)

[R0: Telephonic] - 25 min conversation on past experience. Then 2 easy-medium questions in the rest 15 minutes. Round went perfectly.

Onsite:

[R1: Coding] - 2 standard questions, both were Easy-Medium. I messed up a small detail in the implementation for the 1st question, but quickly recovered after a small nudge from the interviewer. Did the second question flawlessly.

[R2: Coding] - 1 medium and 1 hard question. Did medium questions flawlessly. Hard problem was a graph related problem where we cannot apply BFS but only DFS. Sadly, I assumed both traversal will work just fine, so I focused more on explaining the rest of the answer, complexity and edge cases. As I dove into the implementation, I figured BFS won't work and then I explained how it won't work and switched to DFS. Completed 90% of implementation before we ran out of time.

[R3: Behavioural] - Standard behavioural questions for challenging work, motivation behind joining facebook and so on. This round went above average. I was able to quote past examples from my career to answer the questions.

[R4: System Design] - Design question related to a location based application. I had past experience in building such systems so I latched onto my experience to answer questions related to many design aspects. Sadly, I felt the interviewer wanted to learn this system design from a scratch rather than a lot of ideas that I assumed were present in place. It was definitely a mistake from my end that I did not follow the standard G-R-R-O-K-K-I-N-G answer which they usually want.

Got an email from the recruiter that they are not moving forward and they can't give any feedback at all, which is sad. I know I didn't do well in almost all interviews, is that the reason they cannot share feedback?