We arranged a Skype call with a Senior engineer at UltraSoc. After a first discussion about my projects and an overview on the company, they sent me a text file with an exercise. You have to solve it and send it back at soon as possible. I think he counts the time of how long takes you to make a solution.

first HR telephone interview then followed with a skype interview, questions are OK, things you should already know to apply for this job position. Given a folder with couple system Verilog files couple days before the interview and asked to explain what each line is doing.