The process took multiple months as I was not available. The recruiter did an excellent job in making sure that I took the interview.

The interview lasted 45 minutes and started with details about my previous work experience, which took about 20 minutes. I was then left with 20 minutes for the programming question.

He gave me a problem related to a Binary Search Tree (BST). Obviously, I needed to draw the tree, which is difficult on a phone interview. I started by exploring multiple approaches. He then specifically told me what I needed to do, for example, "Give only a recursive solution" or "You can only store a few things, no extra space."

In the end, I was able to solve it with a minor hint. He was also telling me to fix bugs as I was coding and to indent the code according to his standards.

Overall, it was a good experience, but I did not get the offer. They are looking for people who can code in like 10 minutes, as I was able to code in 15-20 minutes. They want bug-free code and will only go forward with the best candidate. I think even if you make a minor mistake, you are out, as there is someone else who will solve it perfectly. Therefore, try to solve it perfectly!

Another important lesson: If you get the option of a phone versus an in-person interview, I would say go for the in-person interview, as it gives the interviewer the chance to see what you are doing on paper versus imagining that over the phone.

Serialize and deserialize a BST