API Development & Integration ServiceWell-designed APIs that connect your systems, partners, and products reliably
We design, build, and document APIs that developers love to use. From RESTful services and GraphQL endpoints to third-party integrations and webhook systems, we create the connective tissue that makes your software ecosystem work together seamlessly.
APIs are the backbone of modern software. Every mobile app, SaaS product, and microservice architecture depends on well-designed APIs to function. But the difference between a good API and a bad one isn't just technical — it's business-critical. A poorly designed API creates integration friction, increases support burden, and slows down every team that depends on it. A well-designed API accelerates development, enables partnerships, and can become a product in its own right. At A Major, we build APIs with the same care we put into user-facing interfaces. That means consistent naming conventions, predictable error responses, comprehensive documentation, versioning strategies that don't break consumers, and performance that holds under load. Whether you're building an internal API for your microservices, a public API for third-party developers, or integrating with external services like Stripe and Twilio, we deliver APIs that are reliable, well-documented, and a pleasure to work with. We work across REST, GraphQL, and tRPC — choosing the right protocol for your use case rather than defaulting to whatever's trendy.
REST API design & development
Clean, versioned RESTful APIs following OpenAPI standards with consistent error handling, pagination, and authentication.
GraphQL API development
Flexible GraphQL schemas with efficient resolvers, DataLoader batching, and subscription support for real-time data.
Third-party integrations
Stripe, Twilio, SendGrid, HubSpot, Salesforce, and hundreds of other service integrations — built reliably with error handling and retry logic.
Webhooks & event systems
Outbound webhook delivery with retry policies, signature verification, and event log dashboards for your API consumers.
API documentation
Auto-generated, interactive API docs using OpenAPI/Swagger, Redoc, or custom documentation portals with code examples in multiple languages.
Authentication & rate limiting
OAuth 2.0, API keys, JWT tokens, and intelligent rate limiting to secure your API and protect against abuse.
Who this is for
Business owners & product teams
You need software delivered — not just advice. We handle the full build from scoping through to launch, communicating in plain language throughout. No jargon, no handoff gaps, no surprise scope creep.
Engineering teams & CTOs
You need extra capacity or specialist expertise for a specific project. We embed alongside your team, follow your conventions, and ship production-quality code with tests, CI/CD, and proper documentation.
Startups & scale-ups
You're moving fast and need a team that keeps up. We've shipped MVPs in weeks and scaled systems to millions of users. Our founder is personally involved in every project — there's no junior-heavy team behind a senior face.
Not the right fit?
We're a focused agency — we take on projects where we can genuinely add value. If your project isn't a match, we'll say so early and point you in the right direction.
Challenges we solve
API design mistakes are expensive to fix
Once external consumers depend on your API, breaking changes are painful and politically difficult. Getting the design right before launch prevents years of backward-compatibility headaches.
Third-party APIs are unreliable
External services go down, rate-limit you, and change their APIs without notice. Your integration layer needs retry logic, circuit breakers, and fallback strategies.
Documentation is always out of date
Manually maintained docs drift from reality within weeks. Auto-generated documentation from your actual code and schemas is the only sustainable approach.
Authentication and authorization are complex
OAuth flows, API key management, scope-based permissions, and token refresh — getting auth right requires understanding both security standards and developer experience.
Best practices
Design your API contract before writing code
OpenAPI specs let you define endpoints, request/response schemas, and error codes upfront. This enables parallel frontend and backend development and catches design issues early.
Version your API from day one
URL-based versioning (/v1/, /v2/) or header-based versioning — pick one and implement it before your first consumer integrates. Adding versioning later is far more painful.
Use idempotency keys for mutating operations
Network failures cause retries. Idempotency keys ensure that retried POST/PUT requests don't create duplicate resources — critical for payments and order processing.
Generate documentation from your code, not separately
Tools like OpenAPI, tRPC, and GraphQL introspection ensure your docs always match your implementation. Manually written docs are lies waiting to happen.
Frequently asked questions
Related technologies
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