Firstly, there was a written (MCQ) test: 15 questions on Aptitude and 15 on Java. Out of 50-60 odd people, they selected 10-12.

Then, there would have been two Technical rounds and one HR round. I got eliminated in the technical interview round (I have 5.5 years of experience).

Focus on Java fundamentals. You cannot escape just by having knowledge of collections. I was told to do collections in depth, which I did, but nothing was asked on it.

The interviewer was a very knowledgeable person and repeated twice that programming problems are just like life problems. He said, "Just focus on basics and you will sail through very easily."

Why is Java called a secure language?

Question related to locking. A weird calculator which will allow subtraction to happen when an addition operation is happening, but not allow multiplication or division to happen. The same applies for the multiplication/division case: multiply/divide will be allowed, but addition/subtraction not allowed then. How will I implement this in Java?

To check how I code, he asked me to write code for sorting. He asked which is the fastest sorting method.

Accepting that there is no further scope here for me now, I told him that my work involved less of threads and that I worked on servers where it just required a thread pool to accept connections. He then asked me about thread pools:

Firstly, what controls the thread?

Secondly, the life of a thread immediately ends when its task is ended. How does a thread pool maintain its threads then?

What is the basic difference between a process and a thread? I could not answer it properly. He modified it and asked, "What do you understand about a thread?"