+test on a clean environment before demo day. docker is ideal but even just testing on a friend's laptop helps. document your setup steps. if your demo depends on your specific machine, you're one coffee spill away from disaster. this is why you [[test-demo-before-presenting|test on the actual demo machine]], not just your own. make sure to [[restart-server-before-demo|restart services]] so you're not running stale code, and have a [[no-backup-plan-for-failed-demo|backup plan]] for when the environment still surprises you. reproducible environments start with [[not-using-version-control|proper version control]].