Very thorough process that involved a phone screen, followed by an on-site interview with ~6 others.

The on-site interview started with a small/simple paper exercise on basic programming questions. This appeared to be used to seed one of the interviews.

The individual one-on-one sessions were done with talented folks, from those fairly new to long-term veterans of F5. Each interview was unique, but each seemed more of a collaborative investigation than simple questions and answers.

Whiteboard work and general talk-throughs were encouraged. Overall, it felt like a solid interview such that when I received the offer, I was sure that I would be a good fit.

Questions weren't limited to my area of experience, and some were more of a collaborative investigation with a subject matter expert. Working through questions about allocating tight structures and then manipulating them was challenging for on-the-spot work, but was actually fun in the end.