I was sent an email with the interview apoointment and it turned out it was a technical interview although they didn't mention that in the email. It was mostly js questions

First, they assigned a case study to test the programming skills. For my case, it was a simple hotel room booking system which contained both frontend and backend parts. If you are familiar with one of the popular frontend framework, e.g. Vue, React or Angular, and also its ecosystem, the test will be not too hard for you. You have 7 days to finish it. One week after submitting the case study, they invited me to do the first phone screen interview with one of the recruiters. It was basically getting to know your background and working experiences. No technical questions were asked at this interview. One week after the first interview, they inform me to confirm a day on the next week for the second phone screen interview. The second interview was hosted by a hiring manager and a business partner. The questions were mostly about your motivations, working experiences, personalities and few technical questions. Pre-managing why you applied to Trivago and what you did in your previous projects in mind would be helpful to answer. Then one week after the second interviews, they invited me to the third phone screen technical interview which hold by a hiring manager, a project manager and an engineer. The questions basically were your case study, previous projects, understanding of some frontend technologies and what you will do when facing some difficulties. At the end of the third interview, they said they will inform me the result next week. It actually took two weeks and said they had proceeded with another candidate.