Recruiter found me on LinkedIn. Had a quick phone call to scope out interest and skills (and probed for salary range). Second phone call for actual phone screen; asked basic questions about algorithms/data structures, backend, Linux, and other dev tool knowledge. 3.5 hour on-site visit included two coding questions on paper; OO modeling and one more algorithm question on whiteboard; and talk with HR director. Follow-up on-site was a 1/2 hour discussion with an engineer from a different team than in the first round. Technical portions definitely require prep but were well executed on their part. Each meeting wasn't a lecture, but a conversation, and the interviewers were polite. Ultimately, they decided I was a good cultural fit, but lacking enough experience for Level 2.