Uber on-site reject - Where should I improve?
Hello everyone, I had an on-site interview with Uber last week (for Sr.SWE role) and unfortunately I couldn't make it, recruiter got back to me after 3 business days saying it is a reject. I previously posted on tips to prepare (link to that post below)
I had a really positive experience and I felt all my interviewers were nice & conversational and the whole Uber D-bag culture we keep hearing may not be all true. I want to share my experience and maybe get advice on what costed me this opportunity and where I should focus on improving (not just Uber but any MLLFAAANGU in general). I had 4 rounds of 1 hour each
Round 1: Fairly easy round with a Software Engineer (he was possibly L3/L4), asked me an easy coding question on Sudoku that I was able to solve with ease and I was a little surprised this was the only question he had. He was from mobile dev team while I was interviewing for a backend role, could someone from @Uber throw light on whether interviewers could be randomly chosen?
Round 2: Hiring Manager round with typical personality and situational questions. "Tell me about a time you failed, biggest challenge you faced, projects would were proud of" etc.etc. I thought this round went good as well although you can never know what the HM evaluated you on.
Round 3: Arch/System Design round, interviewer was a Senior Engineer. Talked a lot about his work in his team and scaling challenges we both have faced in our careers so far and talked about designing a fault tolerant CC payment service. I went into detail in some areas where he wasn't expecting me to and at the end I felt I did well (although there was one particular methodology of ACID that didn't come to my head at that time). Overall he looked happy.
Round 4: Live coding round where they ask you to code on a laptop, my interviewer was a Senior Engineer. Quite a hard question, I could only come up with a O(n^2) solution, discussed my solution on the white board and unfortunately ran out of time before I could finish the code on my laptop. Since it was past 6pm, my interviewer asked me to email my solution and I promptly did that that very night.
I realize not finishing up your code to a working solution is definitely a red flag but I have known people who have been hired despite a bad coding round.
Could that one bad round be the sole reason for the reject, although my other rounds were good? Particularly System Design round was pretty good and I increasingly know that is the basis of determining hire/no-hire for experienced candidates. I also would like to put out the disclaimer that I'm an above average Software Engineer who do this to earn a living and by no means a rockstar coder/hacker types who invests all his/her freetime into open source projects and develop an app as a hobby.
Thanks for taking the time to read my post and thanks in advance for your response!