Still in the process but so far it has been really pleasant and fast. Applied and received request for phone interview the next day, at the end of the phone screen they told me they wanted to continue with my process and received an email 2 days after with the date and time for the video call with an industrial designer at Fitbit.

3 stage to the interview process. 1st one start with recruiter scanning over the phone. This part of the interview is fairly easy and simple. 2nd round would be video conference call with one of the design lead at Fitbit and go over your projects and background. Usually present 2-3 projects for about 20,30mins. If you pass this stage, then you will be invited to Fitbit headquarter to do an onsite interview with more team members from Fitbit. And this process lasts about 4 hours with 1 hour of presentation+Q&A, and the rest of the time will be interviewing with each designer/engineer in one on one basis.