Very easy, generally testing your knowledge and if you fit the team well. Be prepared to meet the team and have some chats with your future coworkers. The interview itself will not have a very difficult structure in my experience.

I was treated very unprofessionally by HR. The HR individual was extremely late to both interviews (ie: 20 mins late into a 30 mins interview), in both cases, I had to reach out to ensure the interview was still happening. The person was in a terrible hurry both times. After my first interview, I was told that i did great and that they would reach out within a day to schedule my next two interviews but I never heard back.