Meta | Virtual onsite | E4 | US

Recruiter screen: General screening questions. I was asked how much time I wanted to prepare and requested two weeks, although the recruiter suggested more time.

Phone screen:

• Range Sum of BST - A recursive solution was accepted.
• Dot Product of Two Sparse Vectors - I came up with a solution similar to approach 3, and it was accepted.

The interviewer did not ask for time complexities, but I brought them up before ending the call.

I received confirmation within two days that I had advanced to the onsite round. I was again given the option to take a few weeks to prepare, but I chose two weeks and scheduled the onsite within that timeframe.

Onsite:

• Add Strings (with decimal points) - This problem took me longer than it should have.
• Shortest Path in Binary Matrix - I suggested a BFS solution using a deque and was asked to implement it. Unfortunately, I ran out of time and missed one or two lines of code to complete the solution.

• Strobogrammatic Number - I came up with a two-pointer solution.
• I coded a solution that traversed a departing array from right to left while keeping track of the minimum of the returning array and calculating the minimum cost.

• System design (architecture): Design a search system for an existing platform like Threads or Twitter.

• Behavioral - Typical behavioral questions; make sure to have several stories prepared that follow the STAR method. The interviewer requested that I focus my answers on my most recent position.

The entire process took about five weeks, from the recruiter contacting me to receiving the rejection email. The onsite itself wasn't difficult, but I focused too much on studying problems and spent very little time on system design and behavioral questions.