Professional. I spoke to the team lead and another tech writer who guided me through the basic setup and workflow. We talked about the project and then I was given an assignment, which they evaluated soon enough.

I interviewed at several JetBrains' projects. I could only get through the first of two interviews. At the first interview, you need to describe your experience in details and showcase your technical skills. If you speak Russian and expect the interview to be in Russian, be prepared for part of the interview to take place in English. A test assignment follows the first interview. Usually, the test assignment is project-specific and resembles a 'combative' (commercial) task. The entry threshold is high enough. If you have strong technical skills, this may not be enough as you are recommended to have a well-developed technical background.