I had a set of background questions like 'What are you currently working on?', the most difficult programming task I've ever had, and the hardest bug to find, etc.

Then I was asked several simple technical questions about the difference between iteration and recursion, their pros and cons. They were not really difficult.

Which cycle performs quicker?

java for (int i=0; i < 1000; i++) for (int j=0; j < 100; j++)

or

java for (int i=0; i < 100; i++) for (int j=0; j < 1000; j++)

How do you reverse a singly linked list?

I solved it, but made a mistake the first time. After rewriting, I had little time, and the interview ended. That was my fault, I guess.