Several rounds of interviews (four or five). Standard programming questions, not too hard.

Months of project selection hell. For each project, we'd set up a meeting with a manager. We had a phone call, listened to them talk about their log processing pipeline, and discussed my relevant experience, lasting 15-30 minutes total. A week later, I'd receive another recruiter email for the next project. When I'd ask about the previous project, the response was, "They selected someone else." This process would then repeat.

Building a cache data structure