I would stay away from any startup for production workload.

Made the mistake. Never again.

Fly, railway, render. Avoid. All have weird show stopper bugs for any reasonable scale and you will fight against the platform compared to using big cloud.

And big cloud works better even in cases where PAAS is advertised as simpler (google cloud run and build is as easy to setup as railway but you have much more knobs to control traffic, routing, roll out etc)

While I used to think Railway was an amazing service, I had a production workload get broken because they removed a feature without any depreciation period or warning. I now struggle to recommend it for anything more than a hobby project. Vercel has the benifit of being big enough they have to do things properly. For reference https://station.railway.com/questions/smtp-connection-failur...

And their CEO doesn't post selfies with war criminals