Submitted application online. Received email invite for phone interview. This was mostly for culture and fit, and a little business acumen. Invited to come in for a series of in person interviews. 1st was all culture. 2nd was mostly a case study and business acumen. 3rd was with a high level manager, both for culture and business acumen.
Overall I enjoyed the process. The office has the classic start up vibe. Open work area, lunch every day, employees wear t-shirts, dogs running around. It seemed like a really fun place to work, and of course I was disappointed to not move any further, but that's the way things go. They did not provide any feedback, until I requested in an email response. They said I was not selected because of my performance in the case study sections. Fair. We could all do better.
I did read the Glassdoor interview reviews prior to interviewing and it is a little true about what they say, that users felt the interview went well, only to get denied down the road. Which for Flexport, is a good thing, they don't want just anybody.
Advice: take the case study's seriously. This is ultimately what they are judging you on.