i've been grinding leetcode for weeks and feel okay on the coding rounds but the system design piece has me spiraling. i'm a new grad and have never actually built anything at scale. how do you answer system design questions for a payments company when you've literally never designed a payment system?
also how strict are they about new grads doing system design? i've seen some posts say it's lighter for L3 equivalents but i'm not sure if that applies at Visa specifically. any recent data points would really help.
3 replies
careerveteran
for new grad loops, system design is usually scoped way down or omitted entirely. the expectation isn't that you've built a payment processor. it's whether you can reason about tradeoffs. think about it like this: they want to see that you can ask clarifying questions, identify the main failure modes, and not get paralyzed. you don't need to have lived it, you need to show you can think through it.
staff_steph
the key thing with payments specifically is knowing the words: idempotency, exactly-once delivery, retry with backoff, audit trail. you don't have to have implemented these. you just need to be able to say 'i'd want to ensure the operation is idempotent so retries don't double-charge' and explain why. that takes an afternoon to learn, not years of experience.
newgrad_neil
okay this is actually really helpful. i've been trying to design full systems and getting overwhelmed. if it's more about the vocabulary and reasoning i can work with that.