API Development & Integration
REST APIs, webhooks, third-party integrations, and the backend plumbing that holds a real application together.
Most of the bugs in a growing product live in the seams. Auth, billing, syncs, the integration between your storefront and your accounting system. We design and build that layer with real architecture and documentation a future developer can actually read.
Deliverables
- REST or GraphQL API with consistent error handling, validation, and rate limiting
- OpenAPI / Swagger spec generated from the code, so the docs never drift from reality
- Webhook receivers with signature verification, idempotency, and retry logic
- Third-party integrations (Shopify, QuickBooks, Stripe, HubSpot, anything with a documented API)
- Background job queues for the heavy work that shouldn't block a request
- Monitoring, logging, and alerting wired in from day one
Process
- 01
Scope
Map out the endpoints, the data flow, and where third-party APIs sit in the picture.
- 02
Design
Data model, auth strategy, and rate-limit / queue plan agreed before code.
- 03
Build
API ships behind a versioned route. Documentation is generated as we go, not bolted on at the end.
- 04
Handoff
Code, environment variables (safely), runbooks for ops, and a session on how to extend it.
Stack & Tools
- Next.js Route Handlers
- Node.js
- Fastify
- tRPC
- Hono
- Drizzle ORM
- PostgreSQL
- Redis
- BullMQ
- Zod
- OpenAPI
- Sentry
Common questions
Can you integrate with [insert SaaS we already use]?+
If it has a documented API or webhooks, almost always yes. Shopify, QuickBooks Online, Stripe, RevenueCat, HubSpot, Resend, Buttondown, Postmark, Notion, Linear, Airtable - we've worked with all of these in production.
How do you handle webhook reliability?+
Idempotency keys, signature verification on every receiver, and a queue with retries for the work that happens downstream. Webhooks fail in production all the time, so we build assuming they will.
Do you write API documentation?+
Yes. Most of our APIs ship with an OpenAPI spec generated from the code, plus a written README explaining the auth model and the conventions. Documentation that drifts from the code is worse than no documentation.
What about authentication?+
Clerk and Auth.js for most consumer-facing builds, API keys plus rate limits for service-to-service calls, OAuth for third-party integrations. We pick based on who's hitting the API and from where.
What people search for
- REST API development
- GraphQL API development
- webhook development
- Shopify API integration
- QuickBooks API integration
- Stripe integration
- OAuth integration
- third-party API integration
- backend development
- Node.js API development
- TypeScript API development
- background job queue development
- BullMQ developer
- OpenAPI specification
- API documentation
- rate limiting
- idempotent webhook
- API integration agency
Ready to talk about your api development & integration project?
Send us a short note. We respond within 24 hours and we'll tell you honestly whether this is the right engagement for what you're trying to do.