The process started with an online assessment (OA), which included two algorithm questions and one system design-style prompt. The OA felt tailored to Affirm’s product focus, with edge-case-heavy scenarios.

I found it helpful to review past Affirm-style OA questions through Hack2Hire. They had a breakdown of how Affirm tends to test product intuition in technical questions.

After the OA, I had a technical interview with a senior engineer who focused on my problem-solving approach rather than just getting the correct answer. The final round was behavioral, with questions about ownership and collaboration.

Given a stream of transactions, detect if a duplicate transaction appears within a certain time window.