I found an alumnus to refer me. They didn't post intern jobs for graduates this year at my college's career fair.

Monday was a phone interview. The questions were basic about Java data structures. They asked about the Singleton pattern and what situations might lead to more than one instance (multithreading).

Then Friday was the "super day." It was tiring. In the final interview, the interviewer seemed very tired and spoke in a low volume.

Ask a lot about data structures and algorithms. Questions are classical, such as 2Sum, finding the head of a cycling linked list, and deleting the middle node of a linked list given access to it.

For Object-Oriented Design, prepare to design an elevator system.

There will also be some SQL queries, similar to before. I suggest you prepare for a SQL query that returns the top node in a hierarchy structure, for example, returning the manager of the manager of the manager, and so on, until the ultimate boss. I am still not sure about the exact implementation of that.

Finally, cover multithreading concepts, the ATM question, and the producer/consumer question.