I design, build, and document robust RESTful and GraphQL APIs that developers love to use — with sub-50ms response times, interactive Swagger documentation, comprehensive testing, and production-grade security.
APIs are the nervous system of modern software — they connect your mobile app to your backend, your frontend to your database, and your product to the broader ecosystem of third-party services. A poorly designed API becomes a permanent source of developer frustration: inconsistent naming conventions, missing error details, confusing pagination, undocumented edge cases, and breaking changes without warning. I build APIs that are the opposite — intuitive, consistent, fast, secure, and thoroughly documented.
With 20+ production APIs built across fintech, social, e-commerce, and SaaS domains, I bring a developer-centric design philosophy. Every API I create starts with a specification (OpenAPI 3.0 for REST, SDL for GraphQL) before any implementation code is written. This spec-first approach means frontend teams can begin integration immediately using auto-generated mocks, while I build the real implementation. The result is faster delivery, fewer integration bugs, and APIs that are a pleasure to consume.
Beyond design and implementation, I treat API documentation, testing, and monitoring as first-class concerns. Every endpoint gets interactive Swagger docs with request/response examples, error codes with plain-English descriptions, authentication guides, and auto-generated client SDKs. Test suites cover unit logic, integration endpoints, contract validation, and load performance. Production APIs include health check endpoints, request tracing, rate limiting dashboards, and alerting for latency spikes or error rate increases.
Comprehensive api development services tailored to your specific business needs, timeline, and budget.
Production-grade REST APIs built on Express.js or Fastify with OpenAPI 3.0 specifications. Proper HTTP semantics (GET/POST/PUT/PATCH/DELETE), consistent resource naming, cursor-based pagination, comprehensive filtering and sorting, versioned endpoints, and standardized error responses with machine-readable error codes.
Flexible GraphQL APIs using Apollo Server or Mercurius with type-safe schema definitions, efficient resolver patterns, DataLoader for N+1 query prevention, subscriptions for real-time updates, and field-level authorization. Ideal for applications with complex data relationships or multiple client types requiring different data shapes.
Centralized API gateways that handle cross-cutting concerns: authentication verification, rate limiting, request logging, response caching, CORS management, request transformation, and routing to microservice backends. Built with Express middleware patterns or dedicated API gateway solutions.
Seamless integration with external services: payment gateways (Stripe, Razorpay, PayPal), social auth (Google, Apple, Facebook), communication (SendGrid, Twilio), cloud storage (S3, Cloudinary), maps (Google Maps, Mapbox), analytics (Segment), and CRM systems — with abstraction layers for vendor independence.
Interactive documentation that makes integration effortless: Swagger UI with try-it-out functionality, request/response examples for every endpoint, authentication setup guides, error code reference, rate limit information, webhook payload documentation, and auto-generated client SDKs for JavaScript, Python, and other languages.
Comprehensive quality assurance: unit tests for business logic, integration tests for endpoints (Supertest), contract tests for API stability, load testing with Artillery to establish performance baselines, and production monitoring with health checks, P95 latency tracking, error rate alerting, and uptime monitoring.
Outgoing webhook systems for event notification with configurable endpoints, payload signing for security verification, automatic retry with exponential backoff, delivery logging, and a webhook management dashboard. Also incoming webhook handling from payment gateways, CMS systems, and external services.
Implement proper API versioning strategies (URL-based or header-based) with backward compatibility guarantees, deprecation notices, migration guides, and sunset timelines. I help evolve APIs without breaking existing integrations, providing clear upgrade paths for API consumers.
Every project includes these built-in capabilities as standard — not upsells or afterthoughts.
APIs are designed as OpenAPI specifications before implementation begins. Frontend teams can generate mock servers and start integration immediately while the real API is being built.
Every request body, query parameter, and path parameter is validated using Zod schemas that generate TypeScript types automatically — catching bugs at the boundary before they reach business logic.
Standardized error format with HTTP status codes, machine-readable error codes, human-readable messages, and field-level validation details. API consumers always know how to handle errors.
Every request gets a unique correlation ID passed through the entire processing chain — from API gateway to business logic to database queries — making debugging and log analysis straightforward.
Critical operations (payments, data mutations) are idempotent with idempotency key support, preventing duplicate processing from network retries or client bugs.
Sparse fieldsets (select which fields to return), resource embedding (include related data), and response envelope options for API consumers who need different data shapes.
Per-endpoint, per-user rate limiting with Redis-backed sliding window counters. Informative rate limit headers (X-RateLimit-*) and clear 429 responses so consumers can implement proper backoff.
Self-service API key generation, rotation, and revocation with per-key rate limits, scope restrictions, and usage analytics for third-party API consumers and B2B integrations.
Modern, production-proven tools and frameworks I use to deliver reliable, maintainable solutions.
Proven api development experience across diverse verticals with industry-specific domain knowledge.
Secure payment processing APIs, wallet management endpoints, KYC verification integrations, and transaction history APIs with comprehensive audit logging and PCI-DSS compliance practices.
User matching APIs, messaging endpoints, notification systems, content moderation APIs, and real-time presence indicators for dating apps, social networks, and community platforms.
Product catalog APIs, inventory management, order processing, payment gateway integration, shipping provider APIs, and marketplace seller management endpoints.
Public-facing APIs with key management, usage metering, webhook delivery, SDK generation, and developer documentation portals for SaaS products exposing APIs to customers.
HIPAA-conscious API design with encrypted data transmission, audit logging, consent management endpoints, and integration with electronic health record (EHR) systems.
High-throughput device telemetry ingestion APIs, device management endpoints, firmware update distribution, and real-time monitoring dashboards consuming device data streams.
A proven, transparent methodology with clear deliverables at every stage — no black boxes, no surprises.
Define API consumers (mobile app, web frontend, third-party developers), use cases, authentication model, rate limiting strategy, versioning approach, and SLA requirements. I produce a complete API strategy document before design begins.
Design every endpoint as an OpenAPI 3.0 specification or GraphQL SDL before implementation. Request/response schemas, error formats, pagination patterns, and example payloads — all defined upfront so frontend teams can begin integration immediately using mock servers.
Build the API with clean architecture: route definitions, controller layer (HTTP handling), service layer (business logic), repository layer (data access). TypeScript for type safety, Zod for input validation, and comprehensive error handling with consistent error responses.
Generate interactive Swagger UI documentation from the OpenAPI spec, create Postman collections with environment configurations, write authentication setup guides, and produce code examples in JavaScript, Python, and cURL for every endpoint.
Comprehensive test suite: unit tests for business logic, integration tests for every endpoint (Supertest), contract tests for API stability, and load testing (Artillery) establishing P50/P95/P99 baselines under expected and peak traffic patterns.
Deploy with proper versioning, health check endpoints, request tracing, error tracking (Sentry), latency monitoring, rate limit dashboards, and alerting for SLA violations. Include clear deprecation notices and migration guides when new versions are introduced.
What sets my approach apart — backed by real production experience, not just theory.
I design APIs as if I'm the one consuming them — because I often am. Intuitive resource naming, consistent patterns, helpful error messages with actionable details, and documentation that actually gets used. The DX (developer experience) matters as much as the implementation.
API specifications are completed before implementation starts. Frontend teams get mock servers immediately and can begin integration in parallel. This eliminates blocked dependencies and integration surprises during development.
P95 response times under 50ms through efficient database queries, Redis caching, connection pooling, payload optimization, and N+1 query prevention with DataLoader. Performance is designed in, not optimized after.
JWT authentication, input validation, rate limiting, CORS configuration, SQL injection prevention, and OWASP security practices are standard on every API — not upsells or afterthoughts.
Auto-generated Swagger docs that stay in sync with the implementation, Postman collections that are actually maintained, and API changelogs that clearly communicate what changed and what consumers need to update.
As a full-stack developer who builds the frontends and mobile apps consuming these APIs, I have first-hand empathy for what makes an API easy or painful to integrate with. This perspective shapes every design decision.
Common questions about my api development services — pricing, timeline, process, and more.
REST is the right choice for most applications — it's simpler to build, easier to cache, better understood by most developers, and has superior tooling for documentation and testing. GraphQL excels in specific scenarios: when you have multiple client types (web, mobile, TV) needing very different data shapes from the same backend, deeply nested data relationships, or real-time requirements via subscriptions. I recommend starting with REST and adding GraphQL only when REST becomes a genuine constraint.
I use URL-based versioning (e.g., /api/v1/, /api/v2/) for clarity. Breaking changes only happen in new major versions. Minor changes (adding fields, new endpoints) are backward-compatible within a version. Old versions get a clear deprecation timeline (typically 6 months), migration guides, and sunset headers. Consumers are never surprised by breaking changes.
Interactive Swagger UI with try-it-out for every endpoint, request/response examples, authentication setup guide (step-by-step), error code reference with plain-English descriptions, rate limit information, webhook payload documentation, Postman collections with environment configurations, and code snippets in JavaScript, Python, and cURL.
Three layers of testing: (1) Unit tests for business logic with Jest, (2) Integration tests hitting real database via Supertest for every endpoint, including auth, validation, and edge cases, (3) Load testing with Artillery establishing P50/P95/P99 baselines. All tests run in CI/CD pipeline on every push. Postman/Newman for smoke tests in production.
Yes — I regularly integrate payment gateways (Stripe, Razorpay), social login (Google, Apple, Facebook), email/SMS (SendGrid, Twilio), cloud storage (S3), and enterprise systems. I build abstraction layers so your code doesn't directly depend on a specific vendor — switching providers later requires changing one adapter, not rewriting your application.
Input validation with Zod on every endpoint, parameterized database queries (no injection), JWT with refresh token rotation, API key management with HMAC signing, rate limiting per endpoint/user, CORS whitelist configuration, Helmet.js security headers, request size limits, and output encoding. I follow OWASP API Security Top 10 guidelines.
P95 under 50ms for standard CRUD endpoints, under 200ms for complex aggregation queries. This is achieved through database query optimization, Redis caching for hot data, connection pooling, efficient JSON serialization, and avoiding N+1 queries with DataLoader (GraphQL) or eager loading (REST). I establish performance baselines during load testing and monitor in production.
Yes — both outgoing (your API notifying external systems of events) and incoming (receiving webhooks from Stripe, GitHub, etc.). Outgoing webhooks include HMAC payload signing for security, automatic retry with exponential backoff, delivery logging, and a management dashboard. Incoming webhook handlers include signature verification and idempotent processing.
Absolutely. I offer API audit services where I review your existing API for performance bottlenecks, security vulnerabilities, documentation gaps, and design inconsistencies. I provide a detailed report with prioritized recommendations and can implement the improvements directly.
I implement cursor-based pagination by default (more efficient for real-time data) with offset-based as an option for backward compatibility. Pagination metadata includes total count (when practical), next/previous cursors, and per-page limits. For GraphQL, I follow the Relay Connection specification with edges and pageInfo.
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Learn More →Let's design APIs that developers love — fast, secure, thoroughly documented, and a pleasure to integrate with. Free 30-minute API architecture consultation.