Capital One · Primly Community

Did the full Capital One loop for a senior backend role. Here's the play-by-play.

backend_bekah · 4 replies

Just finished the Capital One process for a Senior Software Engineer role on their Payments Platform team. Four weeks start to finish, which was faster than I expected from a bank.

Recruiter screen was 30 minutes, standard stuff. She was actually pretty upfront about the process and compensation bands, which I appreciated.

Technical phone screen: one LC medium (graph traversal, basically a BFS variant with a twist). 45 minutes. Interviewer was sharp and let me think out loud without jumping in too fast.

Virtual onsite, four rounds: Coding round 1: two mediums. HashMap problem and a string manipulation thing. Nothing wild. Coding round 2: a more ambiguous problem where requirements got added partway through. This is deliberate. They want to see you adapt. System design: I got "design a fraud detection system that can process transactions in near-real time." Classic fintech prompt. Talked through Kafka for the ingestion layer, rules engine vs ML model tradeoffs, alert deduplication. Got real questions on the consistency side. Behavioral: 5 questions, pure STAR. "Tell me about a time you disagreed with a technical decision and what happened." "Describe a project where you had to learn something new fast." The interviewer literally wrote notes as I talked.

Offer came back in 8 days. The behavioral round matters more than people think. I've done loops at other fintechs where it's basically a formality. Not here.

4 replies

de_derek

the fraud detection system prompt is literally the canonical capital one design question. i've heard three separate people get a variation of it in the last six months. good to know it's still running.

backend_bekah

yeah i half-expected it and still felt underprepared for the consistency tradeoffs. they pushed hard on "what happens when the rules engine and the ML model disagree." recommend actually thinking through that specific scenario before you go in.

staff_steph

the "requirements added mid-problem" thing is interesting. we do something similar. the point is never to trick you, it's to see if you wrote code that's modifiable or code that collapses when the first assumption shifts.

tired_recruiter

8 days to offer after a virtual onsite is actually fast for a bank. most financial services orgs are running 2-3 weeks post-final round. capital one has invested in their recruiting ops.