A 502 Bad Gateway in this situation usually means the Railway proxy cannot get a valid response from the application process behind it. Since the issue disappears when the cron job is disabled, the most likely cause is that the cron process is interfering with the main web server process.

On Railway, each service is expected to run one primary HTTP server process that listens on the port defined by the PORT environment variable. If a cron job starts another blocking process, consumes the main thread, or crashes the server process, the edge proxy will return 502.

This can happen if:

• The cron task runs inside the same process as the HTTP server and blocks the event loop.
• The cron job restarts the process or exits the main server.
• The cron job consumes too many resources (CPU/memory), causing the server to stop responding.

Things to check:

1. Make sure the HTTP server is always running

Your application must continuously listen on the Railway port:

process.env.PORT

If the cron job runs in the same script and exits or blocks execution, the proxy will return 502.

2. Avoid running cron in the same process as the API server

A safer pattern is to separate them:

• Service 1: API server
• Service 2: worker / cron job

Railway also provides Cron Jobs that can trigger a separate worker service instead of running inside the API container.

3. Check logs during the failing request

Look for messages such as:

• server restart
• port not listening
• unhandled exception
• event loop blocking

If the cron task overlaps with incoming requests and blocks the server thread, the proxy cannot reach the backend and returns 502.

In short, the issue is usually caused by the cron job interfering with the main HTTP process. Running the cron job as a separate worker service or ensuring it runs asynchronously should prevent the 502 errors.