The process was normal, as you would expect.

First, there was an interview with HR, lasting around 30 minutes.

Next, I completed a Codility online assessment with three exercises, which I finished without issues.

After this, I moved on to three rounds of interviews, and this is where everything went wrong for me.

I became very nervous during the interviews and, as expected, I was rejected.

To be fair, the questions weren't that difficult in retrospect. I simply wasn't as prepared as I should have been.

Flatten a tree in levels. Convert an integer to its Excel column representation. Given a linked list, return the integer value that the nodes represent.