Fortunately, I only had three rounds, although I heard it's typically a minimum of four to five rounds.

Interview questions centered on what we would do in that role on a day-to-day basis.

If the opening is product-based, it requires multiple senior management approvals and may take up to three months, as happened in my case.

First Round:

• How would you achieve authorization in an application? i.e., providing different roles/access levels/permissions to different users?
• How would you ensure your application is scalable?
• Is each request to Apache Web Server treated as a thread or a process?
• One sample application use case to design/solve. For me, he gave stock prices of a specific stock at different time intervals and asked for an algorithm/program to calculate the best period to buy and sell for maximum profit (first buy, then sell only). When I gave a solution with two for loops, he asked me to optimize it to avoid additional looping.
• Finally, he gave me a puzzle to solve.

Second Round:

• Asked me to write the architecture for my last application and if I'm having high response times for requests in production (that can't be reproduced on STG), how I would investigate/resolve them.
• How did you achieve caching in the application? What data did you cache?
• How would you implement an in-memory cache if you were to design it? What kind of structure would you use? How do you think Ehcache achieved it?
• Designing an application with a use case for DB archiving & retrieval to test design skills?
• Real-world use case to solve: A railway use case to calculate stops/platforms needed at peak times.

Third Round (Managerial):

• Tell me about yourself.
• Share your role & day-to-day job.
• If you wanted to interact with two applications deployed in different infrastructures, what would you use?
• Which web service would you use: SOAP or REST? Why REST? What standards does it have? Won't it have problems due to the absence of standards?
• You said you developed some core components early on. What was the reason for this rather than assigning it to an experienced lead?
• What considerations would you make while designing an application for performance?
• When an application server crashes, what are the possible reasons? Explain in technical terms.
• Asked me to come up with an estimate given some requirements.