First there was a phone interview, this was to gage expectations (eg expected salary, current notice period) also get a bit of information what experiences you have and why did the Boeing position interest you. This information is fed back to the hiring manager.
The formal interview (face to face - pre COVID days) was a competence based interview... E.g tell me a time when....
There are 5 or 6 questions and the interview will normally last about an hour. Do the required prep and you will be fine.