How to Build a Production-Level Shopify App: A Step-by-Step Guide
If you’ve ever tried to make your own app, you know the struggle all too well: three tabs open with half-updated tutorials, a random GitHub thread that may or may not be correct, and a lot of unanswered “wait, but how do I…” moments.
That’s the reality for most e-commerce managers or developers who want to build a Shopify app.
The information exists, but it’s scattered, inconsistent, and often outdated. Meanwhile, the demand for apps keeps growing because every gap in Shopify’s core platform is a chance to either solve your own business challenge or create something merchants everywhere will use.
That’s exactly what happened when we built Greenlight – Grow Zone Finder, our Shopify app that detects a customer’s USDA grow zone by zip code and times shipments perfectly for their climate.
We’ll use Greenlight as an example throughout this guide, so you can see how an idea turns into a production-level app that clears Shopify’s strict review process.
What Is a Shopify App?
At its core, a Shopify app is a custom extension that plugs into Shopify’s platform to add new functionality. That can mean anything from a shipping calculator to a loyalty widget.
In Greenlight’s case, it meant helping garden centers avoid costly mistakes by showing customers whether a plant was right for their zone before they clicked buy.
Apps come in two main flavors:
Public apps (listed in the Shopify App Store, used by many merchants)
Custom apps (built privately for one merchant, not listed in the store)
Both require serious development chops, but if you’re aiming for the App Store, you also have to clear Shopify’s compliance, performance, and UX hurdles.
Why Build Your Own Shopify App?
Most brands fall into one of two camps:
Filling a market gap.
You spot a missing feature that merchants everywhere could use. Build it, list it, and potentially earn recurring revenue.
Solving your own problem.
Your business needs something Shopify doesn’t provide out of the box. Instead of waiting for a third-party, you build it yourself.
Greenlight was both. Nurseries needed better shipping rules, and once we solved that internally, we realized the same pain point existed industry-wide.
How Do You Develop a Shopify App?
Shopify development isn’t one-size-fits-all. But every app needs the same foundation:
- A database. To store app data like customer info, orders, or settings.
- A server. The backbone that processes requests and talks to Shopify’s APIs.
- Permissions. Apps must request explicit access scopes.
- Authentication. OAuth is mandatory. Merchants must grant access before your app does anything.
- A clean UI. Shopify expects apps to use their Polaris design system.
Then there are the non-negotiables:
- Apps must not reduce store performance (Shopify tests Lighthouse scores).
- Apps must use the Billing API for charges.
- Apps can’t add hidden fees, bypass checkout, or duplicate existing apps.
For Greenlight, this meant making sure our zone-detection widget loaded instantly without slowing down product or collection pages.
Step-by-Step: From Idea to Approval
Here’s the roadmap we followed:
Step 1: Define the Problem
Greenlight started with a simple pain point: “We don’t know when to ship our plants.” If you can’t sum up your problem in one sentence, your app will likely be bloated or unfocused.
Step 2: Map the Workflow
Does your app live in the storefront, the admin, or both? For Greenlight, we needed both: a storefront widget for customers, and admin logic to save zone data with each order.
Step 3: Build the Core
Server, database, authentication, APIs. We kept the UI simple and used Shopify Polaris so merchants instantly understood how to navigate the app.
Step 4: Test, Test, Test
Performance is non-negotiable. We ran Lighthouse audits to make sure the widget didn’t drag load times.
Step 5: Meet the Checklist
Shopify’s app requirements are strict. Clear onboarding, accurate billing, permissions in place, no policy violations.
Step 6: Submit for Review
Shopify’s App Review team puts every detail under the microscope. Expect rounds of feedback.
Why This Matters for Your Business
Building an app isn’t about vanity or chasing buzzwords. It’s about control.
When you build an app, you:
- Own the functionality your business needs.
- Reduce dependency on third-party apps that can shut down or change pricing overnight.
- Create potential new revenue streams by listing publicly.
For e-commerce, the right app isn’t just a nice-to-have. It can be the difference between scaling smoothly or drowning in workarounds.
ECD Digital: Shopify App Development Done Right
At ECD, we don’t just write about app development. We’ve done it. Greenlight is proof.
And while we’re proud of that success, our bigger focus is helping brands build the digital infrastructure they need to scale. That means more than apps:
- 35% average lift in conversions for clients who worked with us on Shopify website development
- 2× faster load times after our performance optimization projects
- Seamless integrations across Shopify, Klaviyo, Rebuy, and other tools that power omnichannel growth
If your tech stack feels patched together, or if you’re eyeing an app idea that could save your team hours of work, let’s talk.
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Written by: Emil Gjorgjijev
Oversees e-commerce operations with a focus on Shopify. Works on optimizing online stores, improving processes, and driving revenue growth. Dedicated to building smooth, high-performing shopping experiences that help brands scale and succeed online.