I had a total of 4 rounds. Most of the discussions focused on algorithms, problem-solving, system design, and a few behavioral questions. The interview process took around 15 days from the first interview to receiving the offer letter.

Round 1: Rotate a 2D array clockwise and anti-clockwise by 90 degrees. The 2D array need not be square.

Round 2: A few questions on projects I worked on. How do you implement throttling for your website? An attacker is constantly hitting your service API. You should send the response as "try after sometime" if the threshold exceeds a certain number of requests. (Sliding window algorithm based time slots)

Round 3 (with Principal Software Engineer): Implement N-tree collapse (anyNode) and decollapse (anyNode). When called, get child nodes (sequence of collapses and decollapses should be considered and should return the child nodes). Discussions on extra space vs. extra time, recursion vs. iteration.

Round 4: Hiring Manager Interview (Director) I found this interview interesting. It was a mix of technical and behavioral questions.

Technical questions: Step 1: Read a row containing username and amount. Step 2: Apply discount and write the same to the table. Step 3: Call a REST API to update the respective user's credit service. We need to process records in batches. He is looking into failure handling cases.

Behavioral Questions: How much time do you spend on coding? What are your career goals? What critical problem have you solved in your career? Last question: Current CTC.