Schema-first, contract-driven APIs that hold up as your product, integrations and team grow — not endpoints bolted on to ship a feature.
APIs become hard to change once anyone is depending on them. These are the situations where investing in the design before the code pays back fastest.
Once an external developer integrates with your API, the contract is hard to change. The cost of getting the design wrong compounds with every new consumer.
The seams between services are where most distributed-systems pain lives. Get the contracts right and the rest of the migration is straightforward.
Multiple clients with different needs talking to the same API is a recipe for endpoints that drift. A schema-first approach keeps the surface area honest.
The previous team is gone, the documentation is stale, and every change feels like a gamble. We reconstruct the contract, write the missing tests, and stabilise it for the team that owns it next.
Each new consumer means another round of bespoke changes. A versioned, contract-driven API decouples your release cycle from theirs.
An API is a contract with everyone who depends on you. We design that contract carefully, then build it once, well — so it keeps working as the product grows.
We design the contract — endpoints, schemas, errors, auth, pagination — before writing the implementation. The schema is the source of truth, not an afterthought.
Versioning, deprecation paths and backwards-compatible changes are part of the design from day one. APIs you can change without breaking your consumers.
Authentication, authorisation, rate limiting and audit logging are decided alongside the schema — not bolted on after the fact.
OpenAPI or GraphQL schemas drive the docs, the client SDKs and the contract tests. Documentation that goes stale because nobody updated it is not a thing here.
Structured logs, traces and metrics are part of the deliverable. When something behaves unexpectedly in production, you can find out why.
API design is one of the easiest things to get superficially right and structurally wrong. Every engineer on the work has shipped APIs that are still running years later.
A five-step path that designs the contract before the code, and treats versioning, security and observability as first-class parts of the deliverable.
Who consumes the API, what they need from it, and what the API must hold up to in production. Constraints first, code last.
Schema, errors, auth, pagination and versioning agreed before any implementation work. Reviewed by the consumers, not just us.
Production-grade implementation against the contract, with automated contract tests so the schema and the code stay in sync.
Deploy with documentation, SDKs and onboarding for the first consumers. Observability, alerts and rate limits in place from launch.
Evolve the API as needs change — versioned changes, graceful deprecation, and a clean handoff to the team that owns it next.
It is faster in the first week to add endpoints as features need them. It is much slower in year two. Here is how the two approaches compare.
| Schema-First | Endpoints-As-You-Go | |
|---|---|---|
| Source of truth | Schema drives code, docs and tests | Code is the truth, docs drift behind |
| Breaking changes | Caught at design review, before code | Discovered when a consumer breaks |
| Versioning | Strategy decided up front, applied consistently | Improvised per endpoint, inconsistent over time |
| Consumer onboarding | Generated SDKs and live documentation | Hand-written docs that lag the implementation |
| Best for | APIs that will outlive the team that built them | Internal endpoints with one short-lived consumer |
Versioning strategy is a design decision we make explicitly — URL versioning, header versioning, or schema evolution for GraphQL. The right answer depends on who your consumers are and how they ship. We agree the strategy before writing the first endpoint.
We treat breaking changes as a last resort. Most schema evolution can be additive: new fields, new endpoints, new optional parameters. When a breaking change is unavoidable, we run new and old in parallel with a deprecation window and clear migration documentation for consumers.
Yes. We are often called in to rescue an API that has drifted from its documentation or has accumulated inconsistencies over time. We start by reconstructing the actual contract from the running system, then plan changes against that baseline.
Auth is part of the API design conversation, not a separate workstream. We work with the patterns appropriate to your situation — OAuth 2.1, JWT, API keys, mTLS, signed requests — and design authorisation rules into the schema so they cannot be skipped at the implementation layer.
Rate limits, structured logs, traces and metrics are part of the launch deliverable. When something behaves unexpectedly in production, you can answer "why" without paging an engineer.
You do. All schemas, code, infrastructure, documentation and contract tests belong entirely to your organisation from day one. No proprietary tooling, no lock-in.
Tell us where you're headed and we'll figure out the best way to get you there.