Phone screen, phone technical interview over Hackerrank, then on-site interview with 2 technical interviews (1.5 hours where you work through a coding problem with them on your laptop -- not whiteboard coding). Aside from that, there's a lunch with a senior staff member, and a more behavioral type interview where they ask you about stuff on your resume.
Really smooth and streamlined process, best of all the companies I interviewed with! They were very accommodating of my job search timing and were flexible with extra time to decide on their offer.
Not going to go into specifics, but they seem to reuse technical questions quite a lot. Check out other Glassdoor posts.
The following metrics were computed from 1 interview experience for the athenahealth Software Engineer (Collector Team) role in Watertown, Massachusetts.
athenahealth's interview process for their Software Engineer (Collector Team) roles in Watertown, Massachusetts is extremely selective, failing the vast majority of engineers.
Candidates reported having very good feelings for athenahealth's Software Engineer (Collector Team) interview process in Watertown, Massachusetts.