went through the full Chime loop about 6 weeks ago for a mid-level backend role. sharing because the system design round caught me off guard in a useful way.
the coding screen was fine. two problems, both medium difficulty, one was a graph traversal variant. nothing exotic. i did them in Python and the interviewer was friendly, asked a few follow-up questions about time complexity but didn't push hard.
the system design round is where it got interesting. they gave me a payments scenario: design a system to process ACH transfers with exactly-once delivery guarantees. i've designed queuing systems before but the fintech-specific angle made me think harder than usual. idempotency keys, failure modes at the bank API layer, reconciliation jobs. they wanted to hear how i thought about the case where money has left our account but the destination bank errored.
that part felt less like a textbook system design and more like: do you understand the actual operational reality of what we're building? i think that's the right question for this company.
behavioral round was two rounds actually, one with hiring manager, one with a cross-functional person (product). they both asked about ownership and times i pushed back on product decisions. classic stuff but they wanted real examples with outcomes, not abstractions.
got the offer. starting in a few weeks. happy to answer specifics.