I contacted a recruiter who posted on LinkedIn that Unity were looking for a front-end developer for cloud services. She set up a phone call for the next week.
The phone call was a great introduction to the company, and gave me more infos on the position. I think the goal of that first interview was to make sure I would be a good candidate for the position, and make sure it really interested me. The discussion was really nice and convivial.
After that discussion, I received a coding challenge that I could do at home. The task itself was really easy, but there was a lot of ways to accomplish the task, so I guess it gives them a good idea on how much you are motivated and if the way you code fits with what they want.
Next step was a phone interview with a dev lead. The discussion focused on my experience and the projets I've worked on previously. There was some more technical questions, but nothing too complicated. I asked a lot of questions and did a lot of research on the company before the interview, and I think that helped.
After that interview, the last step was the hardest, which was half a day at the office, doing multiple interviews with about 10 members of the team. Everyone was really nice and this motivated me even more to get the job.
I really appreciated that the interviews were more about my experience and global programming questions instead of precise technical questions that are not really related to what I would do there.