A Netflix recruiter contacted me on LinkedIn.

A few days later, I had a telephonic conversation with the recruiter where she described the role, and I talked about what I'm doing and what I'm looking for.

After that, there were two more telephonic interviews. Most of the questions were easy, covering topics like BST and core Java.

In the face-to-face interviews, I had four rounds, each lasting 45 minutes, and three of them were technical. They asked me to implement Insertion Sort, check for a valid BST, explain k-means clustering (as I was interviewing for an ML-related role), and design a mobile app that recommends nearby movies currently playing.

Except for Insertion Sort, I think I did well.

I felt the process was smooth, and the people were nice. The only thing I didn't like was that they didn't contact me after the interview. I followed up with them later, and then they said I was not a good fit.

Calculate the number of valid BSTs that can be formed from [1...N] numbers?