The interview process was very long and stressful. After a first initial screening interview with the recruiter I've been asked to complete a live-coding interview and a take-home project. After that there were 4 more interviews: another coding interview, design & architecture, interview with a Hiring Manager and a management interview.
The overall feedback is very negative and the interview was a complete waste of time. Despite having applied for a mobile leading position, I didn't have the opportunity to show my mobile skills because all tech interviews were about data structures and complexity, which is typically a backend problem.
Furthermore, the design interview was a mess: the assignment was to design a log-sending sdk and since I know exactly how Firebase Analytics sdk works I designed something similar. However, according to the interviewer my design choices (which in turn were Google's design choices) were not accurate and he had a better solution. Yes, of course!
The only good thing was the recruiter, Marion: she was really kind and professional and helped me a lot during the whole process.