Service · Engineer
Custom Shopify Apps
When no app in the store does the job — or three of them do it badly and disagree with each other — shopify app development is the honest answer, and we build the one that fits your operation.
- Remix
- App Bridge
- Polaris
- GraphQL Admin API
- Group
- Engineer
- Starts with
- Technical audit
- Delivery
- Git + staging theme
- Handover
- Written documentation
01Overview
Every Shopify app development agency will tell you they can build anything; fewer will tell you when not to. Most operational problems that look like they need custom software are actually solvable with an existing app configured properly, and we'll say so before quoting a build.
When a custom app genuinely is the right call — non-standard fulfilment logic, pricing rules no app vendor targets, a workflow specific to your operation — we scope the narrowest version that solves it, built on Remix, App Bridge and Polaris so it behaves like a native part of Shopify admin rather than an embedded website.
Reliability work goes into the parts that don't show up in a demo: idempotent webhook handling, retries, dead-letter queues and reconciliation jobs, so the app still behaves correctly during a peak sale rather than only in a quiet testing environment.
02The problem
Off-the-shelf apps solve the average merchant's problem well. Complex operations — non-standard fulfilment, custom pricing logic, industry-specific workflows — end up paying multiple subscriptions for partial fits, then stitching the gaps together by hand in spreadsheets.
03You will recognise this if
- Your team maintains spreadsheets Shopify should own
- App subscriptions exceed the cost of building
- No app supports your fulfilment or pricing logic
- You're stitching two or three apps together manually
- Your workflow is specific enough that no vendor targets it
04How we work on it
- 01
Scope the smallest app
We look hard for a way not to build software, because every custom app is a maintenance commitment. If building is the right call, we scope the narrowest app that actually solves the problem, not the most impressive one.
- 02
Embedded and native
Built with App Bridge and Polaris so the app feels like part of Shopify admin, using the same components and navigation patterns your team already knows, not an iframe bolted onto the sidebar.
- 03
Data model and API design
The app's data model and its use of the Admin GraphQL API are designed up front, so it scales with order volume instead of needing a rewrite at the first busy season.
- 04
Webhooks done properly
Idempotent handlers, automatic retries, dead-letter handling and reconciliation jobs, rather than fire-and-forget endpoints that silently drop events under load.
- 05
Operational ownership
Logging, alerting and a runbook so your team knows what broke, when, and exactly what to do about it — not a black box only we can debug.
04What you get
Deliverables, not decks.
- App architecture and data model
- Embedded admin UI (App Bridge / Polaris)
- Webhook and background job infrastructure
- Admin API integration layer
- Monitoring and alerting
- Deployment pipeline
- Operational runbook
- Source code and documentation handover
1# Admin API 2025-072mutation productVariantsBulkUpdate(3 $productId: ID!, $variants: [ProductVariantsBulkInput!]!4) {5 productVariants { id sku price }6 userErrors { field message }7}Delivery pipeline
- Audit
- Scope
- Build
- QA
- Measure
05What changes
- Built only when justified
- We recommend against building whenever an existing app can do the job, so custom development only happens where it earns its maintenance cost.
- Reliable under load
- Idempotent webhook handling and reconciliation jobs mean the app keeps working correctly during high-volume periods, not just in testing.
- Fully owned by you
- Source code, documentation and deployment pipeline are handed over — no dependency on us to keep the app running.
06How an engagement runs
- 01
Audit
We review your current app stack and workflow to confirm whether a custom build is actually justified, before proposing one.
- 02
Scope
App architecture and data model agreed and documented, scoped to the narrowest solution that solves the actual problem.
- 03
Delivery
Embedded app built and deployed with monitoring, alerting and a runbook, with full source and documentation handed over.
07Stack
- Remix
- App Bridge
- Polaris
- GraphQL Admin API
- Node.js
- PostgreSQL
09Questions
More in Engineer
Custom Shopify Apps
Send us the store and the symptom.
A senior engineer reads it, tells you what is actually going on, and scopes only what the evidence supports.