Google

Fairly difficult. I went through 3 rounds of interviews, which began with HR and continued on to timed technical interviews. You could use whichever programming language you were most comfortable with.

The interview process was fair, given the skill level I was at. However, I didn't prepare enough, so I wasn't ready. It's very long; be prepared to solve problems for 5 hours, which can be kind of draining.

They asked me a DFS question, which I solved using iterative DFS. They also asked a Dynamic Programming question. It was a 1-D DP, and I coded a bottom-up solution. Finally, they asked a harder question that involved a monotonic stack.