The first round was with HR.

The second round was a technical screening.

The final virtual onsite had four rounds, each 45 minutes long with a 15-minute break between them.

One of the interview rounds was really difficult to focus on due to significant background noise, such as streetcars.

Technical Screening Questions:

1. Check if two strings are anagrams.
2. Resume walkthrough (e.g., difference between Hibernate and JPA).
3. Questions on Log4j.
4. Given sample code for finding prime numbers between 1 and n. It was technically correct, but I was asked to follow best coding practices and improve it, focusing on JavaDocs, comments, variable naming, etc.

Virtual Onsite Interview:

Round 1:

• What is the Singleton design pattern?
• Have you used microservices before? Please explain from your work experience.

Coding Question: I was given some boilerplate code and asked to design the object-oriented design of Twitter, covering:

1. Posting tweets
2. Following users
3. Unfollowing users
4. Generating timelines.

These were the four methods requested. I used Maps to implement this. You do not need to use databases or tables; in-memory data structures are sufficient.

Round 2:

1. I was asked to construct a binary search tree from a given list of integers.
2. I was asked how I would implement this for a list of objects that need to be sorted based on a specific field. (This can be achieved with generics.)
3. I was also asked to use compareTo() to accomplish this.

Round 3:

1. I was asked to write code to print a Pascal triangle in the console: 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1 1 5 10 10 5 1, etc.

Round 4:

Situational and behavioral questions were asked.