Spotify Android Engineer interview questions

I was contacted by a Spotify recruiter. The interview consisted of the following steps: - HR screening with a few basic Android questions. - Skype 1:1 interview with an Android engineer. In this interview I had some more in-depth Android questions, a coding challenge and a code review task. The coding challenge was to implement in 20 minutes a timer, with the ability to start and stop the counter it and save the state on configuration changes / activity restarts. After this interview I got a detailed feedback and I have been invited to the onsite interview. - Onsite interview: 3 interview (plus lunch, which I'm not sure is taken into account as interview). The first was a cultural interview with the hiring manager and the PO. There I talked about how I work in my current company and I had the chance to ask some questions about the Spotify development process. The second interview was the problem solving one and I had to solve a medium-difficulty matrix problem. The third and last was a "Show&Tell": I had to bring a project and talk about it, explain some architectural decisions and talk about testing choices. Overall the process was nice and the HR team has been very effective and detailed in their feedbacks.