The CTO Podcast with Fexingo · 2026-07-22 · 6 min
Stripe processes hundreds of billions in payments annually. Every one of those API calls must be idempotent - meaning retries don't double-charge. In this episode, Lucas and Luna unpack how Stripe rebuilt its core API to guarantee exactly-once semantics without sacrificing latency. They walk through the architectural choices: idempotency keys, optimistic locking, and a custom transaction log that handles 50,000 requests per second. They also discuss the hard trade-offs - like when to fail fast versus queue for retry, and how Stripe's engineering culture shaped the solution. If you've ever wondered why your payment API is safe to retry, this episode explains the system design behind it. #Stripe #API #Idempotency #PaymentProcessing #SystemDesign #DistributedSystems #EngineeringCulture #Backend #Reliability #TechLeadership #Business #Technology #FexingoBusiness #BusinessPodcast #CTOPodcast #Architecture #Scale #ExactlyOnce Keep every episode free: buymeacoffee.com/fexingo
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