The interviewing is not bad, but it does take some time, and in hindsight I wish they'd done some things differently.
First I had a phone call with HR to discuss what I'm looking for and to get to know the company a bit better.
After that I got a coding exercise that needed to be solved in 2 hours, but it was quite simple.
Once that was done I had 4 interviews: JS knowledge, algorithms, html/css skills, and a call with the hiring manager.
Everyone was very helpful and friendly, so that helped a lot.
But, no one, not once has mentioned that the Software Engineers at HubSpot are expected to do on-call, and I found out about this 3 weeks after starting. This is not a small thing, and should have been called out during the interview, especially because it's not a standard thing in most European companies, and it's a very important detail.
The other thing I feel like was a big miss, is the fact that even tough I was interviewed by around 8 different people, I'm not working with any of the people I was interviewed by. I had a call with the hiring manager, but he's way above my position, the head of a department, and I barely have any contact with this person. So no one on my team met me before I started, I personally think it's important to talk to the people you'll be working with when interviewing.