1. Hackerrank test at first, 90 min, 2 coding questions + 2 multiple choice (from what I remembered, numbers could slightly differ, but it's the overall form)
2. phone interview, ssh into recruiting server, 3 questions based on definition (given code, answer the output), and a coding one. I didn't perform well and didn't get to see all the questions. The recruiter is super nice, patient and kind. I really like the interview questions, they test out your experience and thorough understanding on the subject. It's like coding is on the surface of the knowledge, but the interview questions dig down to what's behind the code. For example, you need to know why certain code would cause a segmentation error. The coding one is basic linked list.
(also before the interview, I didn't know what "ssh into server" gonna be like, and spent too much time on this element. I didn't implement the coding one, but I think you'll just need to know how to code using vim through the terminal. For the definition question, you'll be given an account and password to ssh, then the question would appear on your terminal, so don't worry too much about not having previous ssh experience imo. )