The process was started first video call with HR then they sent me an assignment for the Istanbul office. In the assignment, they want to casino games using JavaScript. After a successful assignment, they wanted to next round for a technical interview. It tooks one and half hours about talking JavaScript, data structures, big o notation, React, and programming concepts. I described as much as possible all questions. In my opinion, the interviewers are a fetish of MDN. They are asking some questions about nobody knows exactly even them and waiting for a fantastic answer. They look perfect but don't have time to write tests in their projects. PS Good developers are not only express all situations, they make it better their work environments.