Product engineering
API Development & Integration
An API is a promise other people build on. We design the contract first — resources, auth, errors, versioning — then build it in Node.js so the teams consuming it stop needing to ask you what a 400 means.
The contract is the product
Most API problems are not performance problems. They are contract problems: an endpoint that returns a different shape when a field is missing, an error body nobody can branch on, a breaking change shipped as a patch, an auth scheme that only the original author understands.
We start from the contract and work back. What resources exist, what each one returns, what every failure looks like, how a client authenticates, how a change is versioned, and what happens when the same request arrives twice. Then we build it — usually Node.js and Express, usually on Cloud Run, always with the contract written down.
- One error shape
- Every failure returns the same structure with a machine-readable code, so a client can branch on it instead of parsing prose.
- Safe to call twice
- Anything that writes takes an idempotency key, so a retry after a timeout does not create a second order, charge or upload.
- Versioned on purpose
- Breaking changes get a version. Additive changes do not. Consumers find out from a changelog, not from a support ticket.
What the engagement covers
- Resource and endpoint design, written before implementation
- Authentication — API keys, tokens or service-to-service identity
- A single error contract with machine-readable codes
- Idempotency, retries and rate limiting on write paths
- File upload endpoints with validation and object storage
- Reference documentation and example requests per endpoint
Technologies
- Node.js
- Express
- REST
- TypeScript
- Google Cloud Run
- Cloud Storage
- Shopify Admin API
Where this helps most
A shared service behind several storefronts
One API serving more than one store, where per-store configuration, per-client auth and a stable contract all matter at once.
A file or document upload endpoint
Uploads that need validation, size and type limits, private object storage and access control rather than a public bucket.
Exposing your own data to a partner
A partner, an agency or an internal team needs read or write access to your commerce data on terms you control and can revoke.
How we deliver
Design the contract
Resources, methods, payloads, error codes and auth are agreed in writing before any of it is built, because that is the part that is expensive to change later.
Build the service
Node.js and Express, structured logging, input validation at the edge, and the write paths made idempotent from the first commit rather than after the first duplicate.
Harden it
Rate limits, timeouts, the failure cases tested on purpose — duplicate requests, partial payloads, upstream outages — and alerts on the ones that matter.
Hand it over
Documentation with real example requests, a changelog, and the deployment pipeline in your own cloud account.
API Development & Integration
REST or GraphQL?
How do you handle authentication?
Will we be able to maintain it?
Can you work with our existing API?
Ready to start with api development & integration?
Tell us about your store and your goals. We'll come back with a clear, honest plan and a transparent quote.