API Integration & Development
Interfaces other systems depend on, designed contract-first so changing them later doesn’t break someone’s Monday morning.
Review your API ↗
What is the difference between API development and integration?
An API is a promise about behaviour, and the code is only the part that keeps it. Development means publishing that promise for others to build on — request shapes, error semantics, pagination, idempotency, auth, limits. Integration means depending on someone else’s promise, which they may change on a schedule you don’t control.
The two jobs share one discipline: write the contract down before writing the implementation. We define endpoints in OpenAPI first, generate types and mocks from it, and let both sides build against the same document. It sounds bureaucratic and it removes the single most common failure — two teams shipping to different assumptions and finding out in staging.
What API work includes
Contract before code
An OpenAPI or GraphQL schema agreed with everyone who’ll consume it, with generated client types and mock servers so integration starts on day one.
Versioning strategy
How you’ll add fields safely, what constitutes a breaking change, and the deprecation window and headers you commit to publicly.
Auth and rate limits
Token issuance, scopes, key rotation and per-client quotas, so one enthusiastic consumer can’t take down the service for everyone.
Idempotency and retries
Idempotency keys on anything that creates or charges, plus exponential backoff and dead-letter handling on the calls you make outward.
Webhooks that survive
Signed payloads, retry schedules, replay endpoints and an event log — because consumer endpoints will be down when you deliver.
Upstream failure design
Timeouts, circuit breakers, caching and explicit degraded behaviour for each third party, decided deliberately rather than defaulting to a 500.
How API work runs
Map consumers and volumes
Who calls this, how often, from where, and what they do when it’s slow. Expected volume changes the design more than the feature list does.
Write the contract
Endpoints, payloads, error codes and pagination specified in OpenAPI and reviewed by the teams who’ll consume it, before implementation starts.
Build against mocks
Mock servers generated from the contract let front-ends and partners integrate while the real implementation is still being written.
Load and failure testing
We test the API at several times expected peak, and deliberately break each upstream dependency to see what your consumers actually experience.
Publish and support
Docs, sandbox credentials, changelog and a deprecation policy shipped with version one — the things that decide whether anyone enjoys integrating.
API Integration & Development FAQ
A single well-scoped third-party integration is usually $4k–$15k; a public API with docs, auth, quotas and a sandbox runs $20k–$70k. The variable is rarely endpoint count — it’s how many consumers you have to keep working while it evolves.
The tools we build with
The stack is deliberately protocol-first rather than framework-first, because the contract outlives whatever we implement it in.
Contracts
GraphQLREST & Webhooks
TypeScriptServices
Node.js
Hono
FastAPI
Go
NestJSData & queues
PostgreSQL
Redis
Kafka
RabbitMQEdge & observe
Nginx
Cloudflare
OpenTelemetry
Grafana
SentryRelated work
Related reading
Need an interface others can trust?
Tell us who’s calling it and how often. We’ll come back with a contract, a versioning policy and a scoped build.