first check if your railway domain itself works (like the frontend-production.up.railway.app one)if that works then it's definitely a custom domain ssl thing, if it doesn't then your app config is the problem

most common issue is the port binding. your app needs to listen on 0.0.0.0 not localhost, and it needs to use railway's PORT env variable. like this:

javascript

// this breaks everything
app.listen(3000, 'localhost');

// this actually works
const port = process.env.PORT || 3000;
app.listen(port, '0.0.0.0', () => {
  console.log(`listening on 0.0.0.0:${port}`);
});

check your deployment logs too ,you should see something like "server listening on 0.0.0.0:8080" or whatever port. if you see localhost or 127.0.0.1 that's your problem right there

Thanks for the steps, ended up actually being an application error (I was running the 'dev' command to start instead of my production static files).