Most merchants default to buying. The App Store is right there, the cost looks low, and installation takes minutes. That default is usually correct - until it isn't.
The merchants who build custom too early waste significant budget on engineering that a well-configured app would have handled. The merchants who buy apps too long past their usefulness accumulate a patchwork of subscriptions, workarounds, and integrations that collectively cost more than a custom solution would have - and still don't do the job properly.
This article gives you a clear framework for making the right call.
Start here: the three questions that matter
Before evaluating any specific app or build option, answer these three questions honestly:
1. Does an existing app solve at least 80% of the requirement well?
Not 80% of the feature list - 80% of the actual business value. An app that covers 15 features but misses the 2 that are mission-critical for your operation is not an 80% solution. Be specific about what matters and what is genuinely optional.
2. What is the total cost of the workaround?
Every app limitation that requires a manual process has a cost. Someone's time, an error rate, a delay in your operation. That cost is real and ongoing, but it rarely shows up in the comparison between an app subscription and a custom build quote. Calculate it explicitly.
3. Is this a standard problem or a specific one?
Standard problems - loyalty programmes, product reviews, subscription billing, upsell mechanics - have mature app solutions built by vendors who have solved them thousands of times. Specific problems - your particular fulfilment logic, your B2B pricing model, your multi-warehouse allocation rules - rarely have app solutions that fit without significant compromise.
The buy case: when an App Store app is the right answer
Apps win when the use case is well-established, the vendor has invested heavily in the solution, and your requirements are close enough to standard that the gaps are tolerable.
Category: customer retention
Reviews, loyalty programmes, referral schemes, email marketing integration. These are solved categories. The leading apps in each have been refined by thousands of merchant implementations. The ROI on custom-building a reviews system instead of using a mature app is almost never positive.
Category: merchandising
Upsells, cross-sells, bundles, product recommendations, recently viewed. Again, solved. The logic is similar across merchants and the apps have iterated to handle the edge cases.
Category: subscriptions
Unless your subscription model has genuinely unusual logic - and most don't - platforms like Recharge and Skio have solved this category. Building custom subscription billing is a significant undertaking and rarely justified below a very high order volume.
Category: basic integrations
If your ERP, accounting platform, or 3PL has a native Shopify integration or a well-maintained connector in the App Store, use it. Custom integration work for systems with existing connectors is almost always premature.
Rule of thumb: if you can find three or more well-reviewed apps in a category with active development and recent updates, that category is probably solved. Buy.
The build case: when custom development is justified
Your business logic genuinely does not fit any existing solution
This sounds obvious, but it requires honest evaluation. 'The app doesn't work exactly how I want' is not the same as 'no app can implement this logic'. Spend time in app documentation and support channels before concluding that custom is necessary.
When it is genuinely necessary: B2B pricing with customer-segment-specific rules, multi-supplier allocation logic, complex fulfilment routing, industry-specific compliance requirements.
You are paying for multiple apps to collectively do one job
If you have three apps whose combined function is to route orders to different fulfilment partners based on product type, inventory location, and customer country - that is a custom integration problem wearing app-shaped clothing. The monthly cost of those three apps, plus the operational overhead of managing their interactions, is the comparison point for a custom build.
App limitations are causing operational problems at scale
API rate limits, webhook delivery delays, sync failures during peak periods. These are signs that you have grown past what an app architecture can reliably handle. At sufficient volume, a custom integration that owns its own API calls and retry logic is more reliable than any app.
Vendor dependency has become a strategic risk
If a single app's pricing change, feature removal, or shutdown would materially damage your operation, that dependency is a business risk worth addressing. Custom development eliminates vendor dependency entirely for the functionality it replaces.
The hybrid approach: often the right answer
Build vs. buy is rarely binary. The most common rational outcome is:
- Use App Store apps for standard categories where mature solutions exist
- Build custom only for the specific logic that is genuinely unique to your operation
- Use Shopify Functions for discount, shipping, and payment customisations that need to live at the platform level
- Build a custom integration layer when multiple apps need to share data - rather than replacing the apps themselves
This hybrid approach captures the speed and vendor investment of the App Store where it works, and applies custom engineering precisely where it creates genuine differentiation.
The decision framework in practice
| Scenario | Recommended approach |
|---|---|
| Standard use case, mature app category | Buy - evaluate top 3 apps, implement the best fit |
| Standard use case, no good app exists | Wait or build - check if Shopify native covers it first |
| Specific logic, workaround is manageable | Buy now, plan to build at higher volume |
| Specific logic, workaround is operationally costly | Build - calculate 18-month ROI to confirm |
| Multiple apps doing one job | Build a unified custom solution |
| App limitations causing operational failures | Build - reliability is non-negotiable |
| Vendor dependency is a strategic risk | Build - own the critical functionality |
The Store Audit is designed to map exactly this decision across your full tech stack - identifying where apps are working, where they are failing, and where custom development creates a clear ROI case.