I agree that legacy apps break 12 factor rules. That&#x27;s why the 12 factor app is &quot;a thing&quot; in the first place. An app which follows them can survive being killed and restarted.<p>I&#x27;ve worked on some legacy migrations and it&#x27;s usually a process of incrementally chiselling out services and cleaning up hard-coded assumptions. Tedious but usually doable.