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API development for products and partner integrations

REST APIs and GraphQL schemas for products, partner integrations and developer-facing platforms that need clear contracts, secure access, documentation and maintainable evolution. We design APIs around real consumers and business boundaries — with compatibility rules, validation, monitoring hooks and handover documentation where the API becomes an ongoing commitment.

Scope of this page

When API development is the actual service

This page is for projects where the API itself is a maintained contract: a frontend or mobile team depends on it, partners integrate with it, or external developers need documented access. If the API is only one part of a broader product backend with business logic, data models and operational workflows, see Backend Development. If the main need is connecting CRM or business systems, see CRM Integration.

  • A frontend, mobile or partner team needs a stable documented API contract.
  • Existing consumers are affected by breaking or undocumented changes.
  • Your product needs a partner-facing or external integration surface.
  • You need ownership, documentation and compatibility rules for an inherited API.
Backend DevelopmentCRM Integration
01  ·  Typical problems

Typical problems we solve

  1. Consumers depend on behaviour that is not documented.
  2. Breaking changes reach frontends or partners without compatibility rules.
  3. Payloads, filtering or pagination make real integrations inefficient.
  4. Authentication and authorisation rules are unclear across consumers.
  5. Partner integrations rely on manual fixes or one developer's knowledge.
  6. The API exists in production but lacks documentation, ownership or a safe change process.
02  ·  What we deliver

What we deliver

What an API engagement produces, scaled to whether the API is internal, product-facing or external.

01

API contract and domain model

Resource or schema design aligned with the product and consumer needs · OpenAPI description for REST APIs or documented GraphQL schema where GraphQL is justified · Clear request, response and validation behaviour

02

Compatibility and consumer safety

Backward-compatibility rules · REST versioning where required · GraphQL schema evolution and field deprecation where applicable · Change documentation for teams or partners relying on the API

03

Access and operational boundaries

Authentication and authorisation model appropriate to the consumers · Role, organisation or partner-level access where needed · Validation, error handling and activity visibility for sensitive actions

04

Usage-aware reliability

Pagination, filtering and payload discipline · Rate limits or usage controls for exposed APIs where required · Asynchronous handling for slow external operations · Monitoring and failure visibility appropriate to the integration risk

05

Documentation and handover

Usage examples, integration notes, API documentation and operational guidance so internal teams or external consumers can adopt and maintain the contract without relying on undocumented behaviour

What we build

What we build

Most API work falls into one of four consumer-shaped engagements — not a list of protocols.

01

Product APIs

Documented API contracts for web or mobile interfaces where frontend teams need predictable resources, validation and change behaviour.

02

Partner APIs

Controlled integration surfaces for distributors, service partners or technical integrators, with access boundaries and documentation matched to real partner workflows.

03

Public or developer-facing APIs

External API surfaces where documentation, adoption, rate limits, compatibility and change communication become part of the product responsibility.

04

API stabilisation and takeover

Existing APIs with missing documentation, breaking changes or unclear ownership that need assessment, contract reconstruction and a safer path forward.

Process

How API delivery works

  1. 01

    Consumers and domain boundaries

    We define who uses the API, which actions and data they need, what must remain private and where the API boundary belongs.

  2. 02

    Contract and protocol choice

    We choose REST, GraphQL, webhooks or a combination based on consumer behaviour, compatibility requirements and operating complexity.

  3. 03

    Implementation and validation

    We implement the agreed contract, access model, validation, error handling and integration behaviour in the appropriate backend stack.

  4. 04

    Reliability and change safety

    Documentation, monitoring hooks, compatibility checks, rate or usage controls where relevant, and test coverage for critical consumer paths are prepared.

  5. 05

    Handover and operating model

    Internal teams or partners receive the documentation and guidance needed to use, extend and maintain the API contract.

External-facing scope

When the API is external-facing

Public or partner-facing APIs may require additional scope: published documentation, consumer onboarding examples, rate or usage limits, compatibility policy, deprecation communication and optional generated clients where they materially improve adoption. The exact scope depends on the partners, data sensitivity and commercial responsibility of the integration.

Inherited APIs

Taking over an existing API

We can assess an inherited API where documentation is missing, consumers depend on unclear behaviour or breaking changes have become risky. The review can map existing endpoints or schema, current consumers, access rules, integration dependencies and the safest path for documentation and future changes.

If the wider system is abandoned, production ownership is missing or the project is already in crisis, see Software Rescue.

Software Rescue & Take-over
After launch

API ownership after launch

APIs used by other teams or external partners need change discipline after the first release. Where relevant, we define:

  • who approves breaking or consumer-visible changes
  • how documentation stays aligned with implementation
  • how deprecations or replacement paths are communicated
  • which tests or validation checks protect existing consumers
  • who owns incident handling for important integrations
Deliverables

API deliverables and handover artefacts

  • Consumer and access model.
  • API contract or schema documentation.
  • Request, response and validation conventions.
  • Compatibility and change rules.
  • Authentication and authorisation notes.
  • Usage examples and integration guidance.
  • Operational ownership and handover documentation.
FAQ

Common questions

  1. Yes. REST is often a clear fit for stable HTTP resources, partner integrations and APIs with multiple external consumers. GraphQL can fit product interfaces that benefit from flexible schema-based reads and controlled evolution. The choice depends on consumers, domain shape, caching, operational requirements and maintainability — not on one being universally more advanced.

  2. Backend development covers the full business logic, data models, authentication, integrations and reliability of a system. API development focuses on the API as a maintained contract: the consumers that depend on it, its documentation, access model, compatibility and safe evolution. If the API is only one internal layer of a broader backend, that work belongs with Backend Development.

  3. We define backward-compatibility rules up front. For REST we use versioning where it is genuinely required; for GraphQL we rely on schema evolution and field deprecation rather than versioning the whole API. Consumer-visible changes are documented, and where it adds value we add validation or contract checks that protect existing consumers.

  4. Yes. Depending on the API we provide an OpenAPI description for REST, a documented GraphQL schema, usage examples and integration notes so internal teams or external consumers can adopt and maintain the contract without relying on undocumented behaviour.

  5. Yes. Partner and external APIs may need restricted scopes, partner-specific permissions, documented test flows, webhook or polling behaviour and clear rules for changes that affect external integrations. The security and operating model depends on the actual partners, data sensitivity and commercial responsibility of the integration.

  6. Yes. We can assess an inherited API, map its existing endpoints or schema, current consumers, access rules and integration dependencies, and plan the safest path for documentation and future changes. If the wider system is abandoned or ownership is missing, that is closer to a Software Rescue engagement.

  7. Where an external or partner API has enough adoption need, generated clients may be considered from an OpenAPI contract. Their supported languages, release process and maintenance responsibility are scoped separately rather than assumed by default.

  8. Yes. Where existing consumers must remain supported, we can assess compatibility requirements and plan a controlled transition rather than replacing the API contract blindly, including integrations that still rely on older protocols.

Adjacent plates

Related services

  1. 01Agent-Ready ArchitectureExpose your API to external AI agents and LLMs safely — MCP endpoints, scoped permissions and audit on every action.Open
  2. 02Backend DevelopmentFor full backend business logic, data models, access control and production reliability beyond the API contract.Open
  3. 03Custom Software & Business PlatformsFor complete systems where the API is one layer of a broader product build.Open
  4. 04CRM Integration & Lead SystemsFor CRM, form and workflow connectors rather than a maintained API product.Open
  5. 05Software RescueFor inherited or failing systems where ownership, deployment or access is already compromised.Open

Discuss your API

Need an API other teams or partners can safely depend on? We can define the consumers, access rules, contract, documentation and change model before implementation or stabilisation begins.

Discuss your API