Multi stage interview.
1. Phone screen with the recruiter (who cold-contacted me).
2. Online Coding Interview (via Coderpad)
3. Take-home assignment.
4. In Person interview - After passing the assignment, was invited to fly to NY (ticket, hotel, uber were all pre-paid/reimbursed) for a series of interviews at the main office.
Interview was 4 sessions
1. Coding Challenge
2. Design Challenge
3. Lunch with 2 engineers
4. interview with Director
For both the phone interview and for the in-person coding challenge, be prepared for a brainteaser which relies heavily on determining complexity using Big O notation. Then be prepared to optimize heavily for reduced complexity (I think this is why they passed on me). Both online and in-person coding exercises were in your language of choice, option to use a laptop in-person was available, but use of whiteboard was heavily encouraged in person.
Director interview was the least positive experience. He spent most of his time staring at his laptop, and not really acknowledging the answers I provided to his questions. There's a couple of possible scenarios I see here, all of which would be easily solvable:
1. He was very busy -- Cut the interview down to 30 minutes, so that he can focus on the interview, quality over quantity
2. They had already decided to pass (or decided mid-interview to pass) -- Just go ahead and send me home, don't waste my time or theirs
3. There was a very large issue that had to be taken care of (Could have handed me off to another interviewer)
The engineers I talked to were all very amiable and seemed to have a solid knowledge of the questions they were asking (showing that they have a pretty standard interview process, which is good).
On the other hand, none of them had seen my resume until they walked through the door into the room, and none had reviewed my submission for the coding assignment (which was a much better showcase of my work than an on-the-spot coding challenge, in my opinion). Everyone seemed very welcoming and it was a pleasant (as possible, although also very stressful) experience. I am a bit disappointed they passed on me, but my guess is they find enough people who are very successful at the challenges (still my guess as to why they passed) that they can be choosey.
If you get invited to interview, it's probably worth it.