Hey everyone, Ben here.
If you’ve been following the journey of DEV and our open source project Forem, you know we’ve always been obsessed with web performance. Way back in the day, I spoke at Codeland about how to make your website so fast it goes viral in Japan, diving into the mechanics of edge caching and how we kept our page loads nearly instant.
Our core philosophy has always been simple: keep the architecture as lean as possible, cache aggressively at the edge, and let the Rails monolith (Forem) focus on what it does best. For years, Fastly has handled our HTML edge caching brilliantly—most of your page requests never even have to touch our Puma servers, which keeps our RAM usage low and our response times in the milliseconds. Fastly continues to be how all the document content on DEV is served.
But while edge-caching static HTML is a well-understood problem, user-uploaded media is a completely different beast.
As DEV grew, we found ourselves drowning in images. Every post cover, user avatar, comment screenshot, and challenge banner is a high-res asset uploaded by our community. Serving billions of these images globally, while keeping page sizes lightweight, eventually led us into a silent scaling trap: a tangled, multi-CDN media pipeline, massive cloud egress fees, and eye-watering monthly bills.
