Why is my deployment failing?

Check the Observability menu first - it shows real-time build and runtime logs and is the quickest way to find the error.

Symptom	Likely cause
Build fails immediately	Missing or invalid Dockerfile - see Writing a Dockerfile
Build succeeds but app won't start	App crashing on startup - check runtime logs in Observability
App starts but isn't reachable	App not listening on port 8080
Environment errors at runtime	Missing environment variable - check container node Config tab

If you're still stuck, the Observability log output will usually point directly at the problem.