“What was the moment this product clicked?” —
A backend or full-stack developer who needs to run server-side applications — not just static sites and serverless functions — and wants them deployed globally without managing Kubernetes or paying for managed Kubernetes overhead. They found Fly.io and found a platform that takes a Dockerfile and runs it near users. They `fly deploy`. It works. They have opinions about Fly.io that include real affection and specific frustrations, which is the relationship one has with a platform they actually depend on.
What are they trying to do? —
What do they produce? —
They're deploying a Phoenix application — Elixir, with WebSockets and a persistent database connection requirement. Vercel doesn't work for this. Heroku would work but the pricing doesn't. They write a Dockerfile. They run `fly launch`. They answer 4 prompts. The app is deployed in 3 regions in 8 minutes. The WebSocket connections route to the nearest region. The database is a Fly Postgres instance in the primary region with a replica in the secondary. They didn't open a cloud provider console once.
Uses Fly.io for 2–6 applications. Deploys backend services, APIs, and full-stack applications that require persistent server processes. Uses Fly Postgres for at least one project. Uses `flyctl` as their primary interface — occasionally the Fly dashboard for status checks. Has configured autoscaling with minimum machines to avoid cold starts on critical services. Has set up private networking between Fly apps. Has been affected by at least one Fly.io incident and has a plan for how they'd respond to another one. Has recommended Fly to developers deploying workloads that don't fit Vercel's model.
Pairs with `supabase-primary-user` for developers who use Supabase for Postgres and Fly for application hosting. Contrast with `vercel-primary-user` for the serverless/static vs. containerized/stateful deployment philosophy. Use with `datadog-primary-user` for production observability on Fly-deployed applications.