Just finished my loop for a senior backend role on Cash App's money movement team. Sharing notes while they're fresh.
Rounds: Recruiter screen: 30 min, pretty standard. She was direct about timeline and comp range upfront, which I appreciated. Technical phone screen: 45 min, one coding problem (graph traversal, medium difficulty), plus 10 min at the end about a past system I built. Onsite: 5 rounds over two days. Two coding, one system design, one behavioral, one cross-functional with a PM.
The system design round was specifically about payments infrastructure. Like, they literally asked me to design a money transfer system that handles double-spend prevention. If you're coming from non-fintech you should spend real time on idempotency keys and distributed transactions before you go in.
The behavioral round surprised me. The interviewer had clearly read my resume. Questions were specific to my actual work history, not generic. She asked me to walk through a time I had to push back on a product decision, and then kept drilling in for specifics. No softball "tell me your strengths" stuff.
The cross-functional PM round was a 30 min product sense conversation. Not a case interview but they want to see you can think like a stakeholder. I almost blew this by being too technical.
Did not get an offer in the end (leveling mismatch, recruiter said). But the process itself was one of the cleaner ones I've been through this year.