I had my first-round interview about three weeks after applying. It consisted of 5-10 minutes of behavioral questions (correlated to their core values), followed by 35-40 minutes of technical questions. The interview was conducted by one of their software engineers.

I moved on to the second and final round, which was a little more than two weeks after the first. The process was the same as the first round, but there were two back-to-back interviews instead of just one.

I thought I did pretty well. I was able to answer their technical questions, and I provided more information regarding my past experiences in the final round after my first-round interviewer suggested I talk more about my relevant experiences (I had asked him for feedback).

I also asked for feedback for my final-round interview, but they said they would send feedback a week after my interview. However, I was rejected almost immediately—I received a rejection email the morning after the interviewers reconvened.

I was baffled, surprised, and upset. I had no idea what I had done wrong. Their email stated they could not provide the specific feedback they had initially promised. So, I still have no idea why I was rejected.

I don't know how to improve from the mistakes I didn't know I made during my final round of interviews. The most frustrating part is their unwillingness to share why, which goes against one of their leadership principles of increasing transparency.

How can I improve my interview skills to actually get the position next year? How am I supposed to improve without knowing where I went wrong, especially since I thought I did well? Transparency would be appreciated.

Coding questions:

• Given a string, find and return the first unique character.
• Given a binary search tree, return the largest sum path from the root.
• Valid parenthesis problem.
• Remove duplicates from a list of integers.
• Implement the following JavaScript methods in Python: on, emit, removeEventListener.