CDN in front of Railway
The app is served straight from Railway, and Railway bills every byte it sends out. A CDN in front of it would proxy esposter.com, cache the build assets at its edge and send them from there, so most of the egress would leave Railway's bill.
Why not: A CDN is a second service to run. It takes over the domain's DNS, TLS and cache rules, and each of those is a place where the app and the proxy can disagree about what is served. The egress it would save is a small fraction of the Railway bill, and most of that saving comes from the app compressing its own assets, which needs no second service (compression). Hosting cost is cut inside Railway and inside this repository, never by adding a service. Every added service is one more thing to maintain and one more source of churn.
Sources
- Railway pricing — egress is billed per gigabyte on every plan.