Shipping to someone who depends on it
Sparkify has a real user running a real shop on it. That changes how you work: there's no such thing as a small deploy, migrations have to be reversible, and 'I'll fix it tomorrow' means someone can't invoice a customer today.
Production and the modernization branch stay strictly separated. Nothing reaches the live shop until it has been used end to end somewhere else first.
Search that matches how people actually ask
Staff don't search the way a database wants them to. They have half a phone number, a first name, or the last six of a VIN. Search now accepts all of it against one query — name, email, phone, and VIN — because the alternative was staff giving up and scrolling.