API Design
Resource modeling, contracts and versioning strategy before implementation.
Service
API development.
REST and GraphQL APIs designed, documented and versioned for the teams and partners who will build on them.
Overview
The service in brief.
What it is
Design and implementation of APIs: contracts, authentication, rate limiting, documentation and the operational tooling around them.
Why it matters
Your API is a product surface. Partners and frontends inherit every design shortcut — good contracts pay compound interest.
Business value
Faster partner integrations, parallel frontend/backend work, and public interfaces that survive versioning.
Capabilities
What's included.
REST & GraphQL
The right paradigm per consumer — documented with OpenAPI or schema.
Authentication
OAuth, API keys and scoped permissions done correctly.
Webhooks
Reliable event delivery with retries, signatures and idempotency.
Rate Limiting
Fair-use controls that protect your infrastructure and your SLAs.
Developer Docs
Reference documentation and quickstarts your integrators can actually use.
Standards
How we deliver.
Contract first
OpenAPI spec agreed before code — frontends and partners build in parallel.
Tested
Contract tests and integration suites wired into CI.
Observable
Per-endpoint metrics, tracing and error budgets from day one.
Documented
Reference docs generated from the spec, kept in sync automatically.
Typical stack
NestJS · PostgreSQL · Redis · OpenTelemetry · Docker.
FAQ
Common questions.
Public API or internal — does the approach differ?
Yes: public APIs get stricter versioning, rate limiting and documentation. We scope accordingly and tell you which standard you actually need.
Can you document an existing API?
Yes — reverse-engineering an OpenAPI spec plus reference docs from a running API is a common, fixed-price engagement.
REST or GraphQL?
Depends on your consumers: GraphQL shines for flexible frontends; REST for partner integrations and simplicity. Written recommendation after discovery.
What does API work cost?
Focused API projects from €4,000; full platform APIs quoted individually with a fixed written quote.
FAQ
Frequently asked questions.
REST, GraphQL, or something else?
REST for public and integration APIs; GraphQL when the client needs graph-shaped data or when you have many consumers with different needs; gRPC internally when latency or streaming matters. We pick the boring right answer.
How do you version APIs?
URI-versioned (/v1/) or header-versioned depending on constraints, additive changes without breaking older clients, deprecation notices in headers, sunset dates in the changelog. Never surprise your integrators.
What about auth?
OAuth 2.1 with PKCE for user tokens, API keys for machine-to-machine, JWT with short lifetimes + refresh, HMAC-signed webhooks. Documented, testable, revocable.
Do you provide SDKs?
Yes — typed TypeScript, Python, PHP or Go SDKs generated from an OpenAPI schema. Kept in sync with the API through CI so drift is impossible.
How do you handle rate limits, webhooks and idempotency?
Rate limits per key with clear 429 responses and Retry-After headers. Webhooks signed and retried with exponential backoff. Idempotency keys on unsafe writes so retries never double-charge.
Do you write API docs?
Yes. Real docs written by the same engineers who built the API, versioned alongside the code, with runnable examples. Not a Postman collection dumped in a PDF.