# 5 Railway.io Config Mistakes That Silently Break Deployments (And How to Fix Them)

If you've used Railway.io for more than a week, you've probably experienced the special frustration of a deployment that looks like it worked — green checkmark, no errors — but your app is completely unreachable. No traffic. No response. Just silence. Most of the time it comes down to a config mistake that Railway doesn't loudly flag. Here are the five that get developers most often, with exact fixes for each. 1. Hardcoding the PORT This is the #1 Railway gotcha and it catches almost everyone at