45 minute phone screen with a VP from engineering. Heard nothing for two weeks. Another 45 minute phone screen with an engineer. Follow up two hour video session with two more engineers about a week later. Final one hour video interview with another engineer a week after that. 5 x one hour-long sessions with engineers. The interviews themselves weren't difficult. Nice people, easy to talk to. However, awful communication from HR. I was never told what the process would be, how long it would take, etc. They never reached out after completing the final interview either. Super unprofessional!