At first, there is a casual talk with HR to let them learn more about your experience.

Then the formal interview is divided into two stages. The first stage is a technical interview. The second stage consists of four rounds, including two rounds of technical interviews, one round of behavioral interview, and one round of leader interview.

Operating system basics and C++ basics. For example, differences between processes and threads, the procedure of a system call, file system details, your favorite feature of C++17, etc.

Implement a simplified shared_ptr class in C++.

Implement the optional feature in C++.

Algorithm problems. It is possible to encounter both medium and hard. I was given a hard one and failed :(