Why External APIs Break Idempotency

Idempotent handlers aren’t automatically safe, especially with retries, concurrency, and most importantly external APIs. Here’s why “idempotent” can still mean duplicate side effects, and what patterns actually work. 🔗 Kurrent (formely EventStoreDB) https://kurrent.io 🔔 Subscribe: https://www.youtube.com/channel/UC3RKA4vunFAfrfxiJhPEplw?sub_confirmation=1 💥 Join this channel to get access to a private Discord Server and any source code in my videos. 🔥 Join via Patreon https://www.patreon.com/codeopinion ✔️ Join via YouTube https://www.youtube.com/channel/UC3RKA4vunFAfrfxiJhPEplw/join 📝 Blog: https://codeopinion.com 👋 Twitter: https://twitter.com/codeopinion ✨ LinkedIn: https://www.linkedin.com/in/dcomartin/ 📧 Weekly Updates: https://mailchi.mp/63c7a0b3ff38/codeopinion 0:00 Intro 3:28 Solutions 4:32 Idempotent 3rd Party & Lookup 5:45 Serialization 7:25 Inbox/Outbox 8:33 Reconcile