"Just Use an App for That"

“Just use an app for that.” I say this a lot. It saves time, it ships faster, and the merchant is happy sooner.

But there are times an app just won’t cut it. No app exists for the specific thing. Or one does, but it quietly kills store performance. Or the functionality is too heavy and too specific for any off-the-shelf solution to handle cleanly, and forcing it in creates more problems than it solves.

That’s when you build custom.

A real case

A merchant wanted to show only the coupon codes that actually applied to a given product and cart, out of 4,000+ running at once. I checked the app store first, before assuming custom was the answer, and nothing handled the full rule set without either falling short or adding real overhead to the product page. So I built it — the full architecture is in the discount engine case study.

The actual decision framework

Use an app when the use case is standard, the app is proven in production elsewhere, and the subscription cost makes sense against the time it would take to build and maintain the same thing.

Build custom when no app exists for it, the available apps hurt performance measurably, or the logic is too complex for any general-purpose app to handle without becoming a liability the first time a rule changes.

The gap between what Shopify apps offer out of the box and what a specific business actually needs is bigger than most people assume going in. That gap is where the work that actually matters lives.