2 interviews in 1 day at the start, one technical and one design. Both were done with proctors who asked questions surrounding the existing team I would be joining. I don't think the interview process was difficult and appreciated the discussion I had during the design interview.

Two screening calls, one interview prep call, and six rounds of interviews. Coding rounds were very much of the "gotcha" variety. Beyond the basic requirements outlined at the start each had an additional, opinionated requirement, and there's no way to discover what that is until it's too late to refactor. If your solution (one of many possible, each with tradeoffs) contains the magic thing, Atlassian lets you through. Otherwise you're out. Atlassian runs a large number of candidates through the interview process, then runs something closer to a lottery than an evaluation in order to whittle down the numbers. Not good for the candidates OR their employees having to constantly run interviews!