You apply through the web page, and soon afterward, a recruiter contacts you to schedule two one-hour technical interviews. Each interview is based on one big problem, with subproblems of increasing difficulty. After passing the technical interviews, you enter the host matching phase. In this phase, you fill out a questionnaire about yourself, and different project hosts reach out to you, scheduling 20-30 minute talks/interviews. Host calls usually consist of describing the project, the team, and your potential role, followed by a discussion of your experience and interests. If, after the host call, both you and the host reply positively, you are hired.

Suppose you have a stream of (timestamp, tag) events.

You need to filter this stream (online), leaving only events with tags that haven't been already encountered in the last X seconds.