Initially, I was supposed to have two interviews, but I ended up having three (all phone interviews).

My first interview focused on my background and a project explanation, followed by a technical question. I was contacted within 10 minutes of its completion for a second round.

I had the second interview a week later with a Development Manager. Again, they asked about my background, how I thought the Uber product works, and potential improvements. This was followed by an open-ended Object-Oriented Design (OOD) question.

Three days later, I emailed my recruiter for feedback. She responded within a couple of hours and asked to set up one more interview.

In my final interview, we went straight into a coding question (OOD and implementation) and ran over time slightly. I was contacted within 10 minutes to set up a call for the next day and received my offer.

Using Object-Oriented Design principles, design a method to check if a Sudoku board is valid. Skeleton code was provided, which was initially passed in as a 2-D array.