The technical questions themselves were not too hard, provided you actually prepared.

• Had a recruiter phone screen.
• Had a technical phone screen. The interviewer told me he liked me, and the recruiter got back to me within an hour with an onsite interview.
• Onsite: I got good vibes. The recruiter got back to me before I even got home, asking me to proceed to the next round. Very fast.
• Had a code challenge.
• Had a request to walk through the code challenge with an engineer. I walked through it and got the feeling he liked it.

Considering how fast they usually responded, I expected a fast response here too, but no such luck. They got back to me a week later with a simple, one-line recruiter email saying they were "going with someone else." I tried to reach them but got no further response. Very rude.

Find the square root of a number without using the square root method.