A Shopify app for the one thing
no existing app does the way you need
The Shopify App Store covers the common cases well, discounts, reviews, upsells, and runs thin exactly where your business is not common: a pricing rule tied to a supplier cost you track yourself, an approval step your team needs before an order ships, a sync to a system the App Store never heard of.
What it is
A custom Shopify app is a separate service, typically a small backend plus an admin screen embedded in Shopify through App Bridge, that does something the platform and its App Store do not cover out of the box. It talks to Shopify through the Admin and Storefront APIs and reacts to store events through webhooks: an order placed, inventory changed, a fulfillment created.
This is different from a theme. A theme changes how the storefront looks and the checkout flows; an app adds logic Shopify was never going to ship, like a pricing rule that reads your actual supplier cost before showing a price, or an approval queue that holds high-value orders for a manager to confirm before they go to fulfillment.
When you need it (and when you do not)
You need a custom app when the logic is specific to your business and no combination of existing apps covers it cleanly, or when stacking three App Store apps to approximate what you need creates more fragility than one app built for the exact case. Supplier price syncs, multi-warehouse stock rules, loyalty logic tied to your own point system, and order approval workflows are common reasons.
You do not need one if an existing app already does what you want, even imperfectly, and the cost of a few dollars a month in app fees is clearly less than the cost of building and maintaining custom code. We check the App Store first in every engagement and will say so if that is the honest answer.
How we build it (stack, components, integrations)
Most apps are a small FastAPI or Node.js backend running on your own infrastructure or a managed platform, talking to Shopify through GraphQL for data and webhooks for events. A Redis-backed queue handles anything slower than a webhook’s response window, a supplier sync, an image generation step, a bulk price update, so Shopify never sees a timeout.
The admin UI lives inside Shopify’s own admin through App Bridge and Polaris components, so your team does not learn a second interface. Where the logic can run natively in Shopify Functions, cart and checkout customizations, discount logic, we use that instead of a separate service, because it is faster and has one less moving part to maintain.
What to watch (risks, cost of ownership, vendor lock-in)
Shopify’s API versions roll forward every quarter and deprecate old fields on a schedule; an app that is never touched after launch will eventually break on an API bump, so budget for occasional maintenance, not a one-time build. If the app becomes central to how orders are processed, losing access to it, through a lapsed hosting bill or an unmaintained dependency, stops your checkout. We build with monitoring and a documented runbook specifically so that risk has an answer before it becomes an incident.
Testing matters more here than on most builds, since an app bug can silently fail an order sync rather than show an obvious error. We run every app against a staging store with realistic order volume before it ever touches your live store, and we keep a rollback path ready in case a Shopify API change breaks something after launch.
Price and timeline
| Option | Price | What it covers | Timeline |
|---|---|---|---|
| Single-purpose app | from $2,500 | One integration or workflow, one admin screen | 3 to 5 weeks |
| Multi-workflow app | from $6,000 | Several integrations, job queue, own database | 5 to 8 weeks |
| App plus ongoing sync | from $10,000 | Full operational app with supplier or ERP sync, monitoring | 8 to 12 weeks |
Running cost is usually $20 to $80 a month in hosting and queue infrastructure, separate from any Shopify plan fee.
Related
This builds on Shopify store development with a custom theme when the storefront also needs work, and connects well with order management system once order volume grows past what manual review can handle. See the development service page and the e-commerce service page for package details. For a real Shopify build and a real marketplace automation layer, see the D2C store Thailand audit and rebuild case study and the ProBay marketplace case study.
Have a workflow no Shopify app quite covers? Get in touch and we will check the App Store honestly before proposing custom code.
FAQ
How much does a custom Shopify app cost?
From $2,500 for a single-purpose app: one integration, one admin screen, clear scope. $6,000 to $12,000 is typical for an app with several workflows, a background job queue, and its own small database.
How long does it take?
3 to 8 weeks depending on how many Shopify objects the app touches and whether it talks to an external system like a supplier API or ERP.
What is the stack?
Node.js or Python backend, Shopify's Admin and Storefront GraphQL APIs, webhooks for real-time events, Shopify App Bridge for the embedded admin UI, and a job queue (Redis-backed) for anything that takes longer than a webhook's timeout allows.
Who owns the app and its code?
You. The app is registered under your Shopify Partner account or your store directly if it is private, and the source code sits in your own repository from the start.
Who maintains it after launch?
You, your team, or us on a support plan. Shopify's API versions change roughly every quarter, so a maintenance plan matters more here than on a simple theme.