1st round: 30 minutes with a developer on Codility, doing one medium question.

Final round: Four 45-minute sessions back-to-back on Codility, with a 15-minute break in between. Each interviewer will usually give one easy or medium question, which you are expected to complete in approximately 30 minutes with a close-to-optimal solution. They will also give you 2-3 behavioral questions, focusing less on specific projects on your resume and more on prompts like, "Tell me about a time when you... xyz."

Given a linked list and an int k, how would you swap the value of the kth element from the head with the kth element from the tail?

Given an n-ary tree, how would you perform zigzag level-order traversal?