How I moved Call Kent podcast episode processing off my primary Fly.io app server and onto Cloudflare Queues and Containers: what broke, what I missed, and whether it was worth the complexity.

Kent C. Dodds is a well-known software engineer, educator, and open-source advocate renowned for his expertise in JavaScript and React. Through his blog, courses, and conference talks, Kent shares insights, best practices, and practical tips on front-end development, testing, and software engineering. Developers can learn from Kent's extensive experience and deep understanding of the JavaScript ecosystem, gaining  insights into building modern web applications with React and other technologies.

Kent C. Dodds

Kent C. Dodds shares how a long podcast episode caused his Fly.io primary server to hit 400-500% CPU load, forcing him to offload FFmpeg processing to Cloudflare Queues and Containers. The new architecture enqueues a job from the app, a Cloudflare Worker forwards it to a Container that runs FFmpeg, uploads results to R2, and POSTs a signed HMAC-SHA256 callback to the app. The post covers the before/after metrics (85% reduction in peak load), cost tradeoffs between Cloudflare and a dedicated Fly.io machine, and several implementation mistakes caught after the initial PR: a counterproductive local fallback, container lifecycle issues with sleepAfter, and a queue worker that blocked for the full transcode duration. The conclusion reinforces a 'start simple, iterate when reality demands it' philosophy.

Offloading FFmpeg with Cloudflare

Why the primary machine was the worst place for this

<p>Why not just run your own high end cpu server with nvme in raid. saves burning money in the cloud.</p>
