Just finished the PayPal backend SWE process for a mid-level role on their payments infrastructure team. Sharing because I couldn't find much recent signal when I was prepping.
Timeline: recruiter reached out, phone screen 10 days later, virtual on-site 3 weeks after that. Offer came 8 days post-onsite. Roughly 6 weeks start to finish.
Phone screen: 45 min with a hiring team eng. One coding problem, medium LeetCode-style, string manipulation with some edge cases around unicode. They asked me to think out loud, and the interviewer was friendly but clearly timing me. Got through it.
Virtual on-site (4 rounds): Coding 1: graph traversal, BFS. Not hard but they asked what happens if the input graph has cycles. Edge case probing was the real test. Coding 2: interval merging. Again, medium. The interviewer stopped me partway and said "assume the inputs are now streaming, how does your approach change." that pivot caught me off guard. System design: design a fraud detection alerting system. This was genuinely interesting. They pushed hard on latency vs. accuracy tradeoffs. I knew Kafka but they wanted me to justify it. Behavioral: classic STAR format. "Tell me about a time you had to push back on a deadline." "Describe a system you built that didn't work as expected." The interviewer took notes, which I noticed.
Overall vibe: professional, not warm. They're a big company and it feels like one. The interviewers were competent but not trying to sell you. If you want culture fit validation, look elsewhere.