I applied online. The process took 8 weeks.

The process consisted of a questionnaire form about my expertise, an online interview with 2 rounds (DSA & behavioral), and an onsite interview with 3 rounds (2 DSA, 1 system design). The interviewers are random, which I feel creates a wide variance in the experience. For example, the online DSA wasn't a leetcode problem at all, but a rather easy practical coding question which I aced. The onsite DSAs were variations of leetcode problems, and it's safe to say I didn't study enough. I also signed up for a mock interview for system design, but the mock interviewer gave a problem that was nothing like the actual interview, and I walked away from it feeling duped. Therefore, I wouldn't really recommend doing the mock interview since I can hardly imagine the incentive an internal employee has to hold one.

Prefix sum question with some variations.

A variation of subsequences involving tries.

Design a subscription billing service for an AI service.