Depends on the individual team and domain of the selection to team. Some domain have 3 to 4 rounds of interviews. Some have online tests. It is depends.

Freelancing in the name of interview. I had informed hiring manager and HR about my CTC and the offer in hand before initiating hiring process. I went through 1 online programming challenge, 2 days of hardcore programming assignment and 2 days of face to face. In the end official statement of hiring manager was "Your feedback has been excellent in all the rounds and I would love to have you in my team at any cost, that said, I don't think we can pay even your current salary". What I hated the most was the interviewer was not even interested in knowing my thought process and just wanted the assignment to be completed. After two days of home work the interviewer just took the code and asked me to make it run on their system. He wanted me to write complete project (with samples, hardcore shape intersection algorithms, unit test cases and build scripts). At one time he did tell me that they are writing similar poc and was happy with my design because all my api's were running in O(1). Be careful about Aero division guys and do take things in writing before you start interviewing with them.

I was contacted by a consultant for Honeywell Aerospace. The first round was a bogus time pass online test that even a school student can qualify. Next was supposed to be some Hackathon round and I had read such horrible reviews on glassdoor regarding the Hackathon that I decided I will not waste my time going there. But the consultant persuaded me to change my mind and I did. On the day of the Hackathon, I guess the recruiters were struck by lightning and they suddenly decided to go with a normal PI round, which was again super easy. I got a very positive feedback from them and they assured me that they would call me the following week for another coding assessment. This was three weeks ago and they of course never called. And just now, I have received a called from a different consultant regarding the same position at the same division in the same company! So this compels me to write my review because this company is extremely whimsical. They ask sub standard questions, and have no regards for the candidate's time. Of course they do not appreciate the fact that the candidate has to take at least a half day off to cater to their stupid whims and fancies.