I originally applied online in Sept. and received a follow up email the next week. 3 weeks after responding to this I didn't hear anything back, so I sent a follow up message. What a great idea this was! After the follow up message everything moved forward on a weekly basis.
Initially, there was a phone interview with the hiring manager for the position, then a short one with HR. During this second one they told me they wanted to schedule an onsite interview day with a presentation. Don't sweat this part- just go in, be yourself, and talk about what you've done.They are looking for passion and curiosity just as much as content.
After the presentation there are several one-on-one interviews. For this job, there was only 1 short technical interview where they asked about simple MATLAB stuff. Other than that there was an HR interview with standard HR questions, another interview with the hiring manager, and an interview with the head of documentation. The latter interview was mainly about making sure this was something I wanted to be doing.
After this, I got an email back from HR a few days later and had another phone interview with someone that was absent during my onsite day. The day after that they started background/reference checks, and I got the offer the following week, 3 months after first applying online.