I expect you tried more than once and it gave you the same status code. The reason for this is probably because of the size of your code that you are uploading. Is your gitIgnore setup correctly? As you might be uploading something like node_modules.

I’d treat the 503 as an upload-stage Railway issue, because railway up uploads your local source before Railway builds or starts the app.

Please check:

railway whoami

railway status

railway upgrade --check

railway up --verbose

If the CLI is outdated, run railway upgrade and retry.

If it still fails specifically while uploading code, that points more toward Railway’s source-upload endpoint than your application code. A temporary workaround is to deploy from a connected GitHub repo instead of the local CLI upload path.

If it keeps happening, send Railway the CLI version, UTC time of failure, project/service ID, and the relevant verbose output, with any secrets redacted.