One of the questions brands considering Shopify in Türkiye ask most often is this: “What happens if there is no ready-made Shopify app for the system we use?” Our answer is clear: set up properly, Shopify can integrate with almost any structure. If a ready-made app exists, we use it; if not, Booster Wizard builds a custom Shopify app for your store.

As an official Shopify Partner, in this article we explain what a custom app is, which Shopify tools it is built with, which needs in Türkiye we most often build them for and how the process works.

The Difference Between Ready-Made and Custom Apps

The apps in the Shopify App Store are public apps, built for many stores to use, and they go through Shopify's review before being listed. These apps cover common needs well, but they do not fit every brand's workflow exactly.

A custom app, on the other hand, is built only for your store. According to Shopify's developer documentation, an app with custom distribution is installed on a single store or on stores belonging to the same Plus organisation, and it does not go through Shopify's app approval process. New custom apps are created and managed in Shopify's developer panel, the Dev Dashboard; custom apps created directly in the Shopify admin before 1 January 2026 continue to be managed from the admin as legacy apps.

A custom app is written around your store's business rules. It is not a general product shared with other brands; you decide which data goes where, when and according to which rule.

The Building Blocks of a Custom App

Shopify offers official developer tools that give access to almost every layer of the store. We decide which ones to use on a project after the needs analysis.

The GraphQL Admin API

We use Shopify's GraphQL Admin API to read and write store data such as products, stock, customers, orders and discounts. Shopify classified the REST Admin API as legacy as of 1 October 2024, and since 1 April 2025 it has required new public apps to be built exclusively with the GraphQL Admin API. We choose the same current foundation for custom apps.

Webhooks

Webhooks let Shopify send your app a near-real-time notification when an event happens in the store. A new order, a refund or a change in stock level can be passed to the ERP or the shipping system without constant polling. Because Shopify does not guarantee that every notification will arrive, we also set up a reconciliation step that runs regularly, so a missed record is never silently lost.

Shopify Functions

Shopify Functions are small pieces of code that customise Shopify's backend logic during checkout: discount rules, hiding or reordering delivery options, showing payment methods conditionally and cart validation are examples. One important detail: according to Shopify's documentation, only stores on the Shopify Plus plan can use custom apps that contain Functions. On other plans, public apps containing Functions can be used through the App Store, so we plan these kinds of rules together according to your plan.

Checkout Extensions

Checkout UI extensions are used to add custom fields, information boxes or extra content to checkout. Extensions added to the information, shipping and payment steps work only on Shopify Plus stores. The Thank you and Order status pages, meanwhile, can be given content such as surveys, digital download links or shipping information.

Metafields and Metaobjects

Metafields add extra fields to existing records such as products, customers or orders; for example, an ERP code can be added to a product or a dealer group to a customer. Metaobjects let you create entirely new record types of your own, such as a size chart or a store branch. Custom apps keep data coming from external systems in these structures in an orderly way that can be edited from the admin.

Shopify Flow

Shopify Flow is a free Shopify app that lets you build automations made of triggers, conditions and actions based on events in the store, and it is available on the Basic, Grow, Advanced and Plus plans. The action that sends an HTTP request to an external system is offered on Grow and higher plans, while tasks that custom apps add to Flow can be used on the Plus plan. We handle simple rules with Flow and complex integrations with a custom app.

Integrations Run on the Server, Not in the Shopper's Browser

One of the most important features of the custom Shopify apps we build is that the work happens on the server side. The app's own server talks to Shopify directly through the GraphQL Admin API with an access token, and webhook notifications arrive at this server rather than in the browser. Shopify Functions, meanwhile, are run by Shopify on its own infrastructure, exactly when needed during checkout.

This means there is no need to add extra scripts to store pages, to be loaded in the shopper's browser, for an ERP, shipping, e-invoicing or marketplace integration. Where customisation is only possible with client-side scripts injected into the page, every new requirement means one more piece of code the shopper has to download and run, and over time this load slows the store down. Server-side integrations run in the background without affecting the speed of the storefront.

The Integrations We Build Most Often in Türkiye

The custom apps we write for brands selling from Türkiye mostly arise from the following needs:

  • Support for payment provider integration: matching collections to orders, tracking the refund flow and passing payment data to accounting.
  • Carrier integration: creating shipments automatically from orders, printing barcodes and labels, and passing the tracking number to the order and the customer.
  • E-invoices and e-archive invoices: turning orders into invoices through your integrator and writing the invoice details back to the Shopify order.
  • Marketplace sync: managing the flow of products, stock and orders with Trendyol, Hepsiburada and n11 from a single centre.
  • ERP and accounting sync: two-way transfer of product, price, stock, account and order data with systems such as Logo, Mikro or Nebim.
  • B2B rules: price lists for specific dealer groups, minimum order quantities and approval-based order flows.
  • Custom reporting: reports your management team needs by channel, campaign, region or product group.
  • Migration via APIs: reading products, customers, past orders and URL redirects from your old platform's API and writing them to the new store with the Shopify Admin API.

Let us make one distinction clear on the payments side: the payment solution that takes card details at checkout works through the provider's own app under Shopify's approved payments partner programme, and that programme is invitation-only. The apps we build do not replace this solution; they complete the matching, reporting and accounting processes around it.

Our article on how payments, shipping and e-invoicing are generally set up on Shopify: Shopify in Türkiye: payments, shipping and e-invoicing

The Development Process: From Analysis to Maintenance

On every custom app project we follow these steps:

  • Analysis: we review your current systems, your teams' daily workflow and the API or web service options of the other system.
  • Data flow design: we set out in writing which data moves in which direction, with which trigger and how often, and what happens when something fails.
  • Development: we build the app on the GraphQL Admin API and webhooks, with only the permissions it needs.
  • Testing: without touching the live store, we try it out with realistic data on a development store created from the Dev Dashboard.
  • Launch: we install the app on the live store and closely monitor records and error logs in the first days.
  • Maintenance and version tracking: we keep the app up to date as Shopify and the other system change.

Version tracking is a real work item in this process. Shopify releases API versions every quarter, and each stable version is supported for at least 12 months. We therefore adapt custom apps to new versions at regular intervals and update calls that are being retired before their deadline.

One Custom App Instead of Many Apps

In some stores we see a separate app installed for every small need, and over time dozens of interdependent pieces build up. Bringing these needs together in a single custom app has the following advantages:

  • Fewer scripts: less third-party code is loaded on the storefront; because the integration logic runs on the server, page performance is protected.
  • Lower recurring costs: instead of several monthly app subscriptions, you plan the maintenance of a single solution.
  • Data ownership: your data stays in a flow where you decide what information is kept.
  • A single workflow: order, invoice, shipping and stock steps work with consistent logic rather than through apps that are unaware of one another.

Our detailed article on speed and performance: Shopify speed and performance

What Do We Do When a Ready-Made App Exists?

Custom development is not always the first choice. If there is an app that meets the need well, is kept up to date and has reassuring user reviews, we install and configure it. We move to a custom app only when ready-made options do not meet your workflow, when several apps working together cause problems, or when no connection exists at all for your systems.

This approach makes Shopify a strong option for Türkiye-focused brands as well. Local needs are met either with a ready-made app or with custom development, while Shopify's infrastructure, theme flexibility and readiness for selling abroad stay in place at every stage of the brand's growth.

Our article on why we recommend Shopify to brands selling in Türkiye too: Why Shopify for brands selling in Türkiye?

Conclusion

“There is no ready-made app for that” does not have to be a reason not to move to Shopify. Thanks to the GraphQL Admin API, webhooks, Functions, checkout extensions, metafields and Flow, Shopify can talk to your ERP, your carrier, your e-invoicing integrator and your marketplaces. We assess ready-made solutions first, and where they fall short we build a custom app for your store and take care of its maintenance.

If you are planning an integration or a custom app to connect your systems to Shopify: See our Shopify Partner services