I made a connection with a professor at Harvard who had received money from a grant. I asked for a job, when none were advertised on the Harvard website. Although the professor had help with others, I got brought on nonetheless

Applied online. On the day of the interview, met several people for 30min or so throughout the day. Had a follow up interview with couple of other people on another day. Interview questions were mostly prior work experience related and approaches to solving current problems, there were some behavioral type questions, but not a lot. The whole process was completed within few weeks.