A custom app is justified when store-specific logic, internal workflows, or an integration cannot be handled cleanly by the theme or an existing product.
The engineering work is only part of the decision. A useful app also needs a clear owner, controlled permissions, reliable background processing, and a maintenance plan.
Key takeaways
- ↗Validate the workflow before choosing the architecture
- ↗Request only the access the app needs
- ↗Plan for webhooks, retries, and operations from the start
01
Confirm that an app is the right layer
Begin with the business workflow and its users. A theme extension may be enough for storefront presentation, while a backend app is appropriate for protected data, scheduled work, or integrations with external systems.
- ↗Who uses the feature?
- ↗Which Shopify data must it read or change?
- ↗What must continue working when no one has the app open?
02
Model data and permissions early
List the objects the app owns, the Shopify resources it touches, and how long data should be retained. Request the smallest practical access scopes and make permission changes visible in the development plan.
03
Use the supported authentication path
Shopify’s CLI and app templates handle the standard token flow for most apps. Build around the current GraphQL Admin API and distinguish between requests made for an active user and background work that needs offline access.
Practical note: Avoid implementing an authentication flow from memory. Start from the current Shopify app template and documentation.
04
Treat webhooks as unreliable delivery
Webhook handlers should verify requests, respond quickly, and move expensive work to a queue. Events can arrive more than once or out of order, so processing should be idempotent and observable.
- ↗Verify webhook authenticity
- ↗Store an event identifier
- ↗Retry safely
- ↗Log failures with enough context to investigate
05
Design for operation after launch
Document environment variables, data retention, deployment, monitoring, and support ownership. A small internal integration still needs a recovery path when an API request fails or Shopify changes an adjacent workflow.
Further reading
Written by Mo Oumha
Shopify and full-stack developer working on themes, custom storefront features, integrations, and performance.
About Mo ↗