API Development
Production-grade APIs with typed validation, idempotency keys, structured error responses, and tiered rate limiting. The same patterns Stripe uses, built for your business.
Why Custom API Development?
Most businesses start with Zapier or Make to connect their tools. That works until you need conditional logic across three systems, error handling that actually recovers, or processing volume that makes task-based pricing unsustainable.
We build APIs the way Stripe builds APIs. Every endpoint gets typed request/response validation through Zod schemas. Error responses include machine-readable error codes, human-readable messages, and documentation URLs. Rate limiting is tiered per endpoint based on cost and risk. Idempotency keys prevent duplicate operations on retries. API versioning through headers means your integrations never break on updates.
The architecture uses class-based dependency injection throughout. Every route, handler, and middleware is a class that receives its dependencies through the constructor. No global singletons, no hidden state. This means every component is independently testable, and swapping implementations (in-memory store for Redis, local auth for Supabase) is a one-line change.
Deployed on your infrastructure with Docker, backed by PostgreSQL via Supabase, with optional Redis for multi-instance rate limiting and caching. Sentry for error tracking, structured logging for debugging, and health check endpoints for uptime monitoring.
Common Use Cases
What we build
Production-grade integrations for businesses that have outgrown no-code tools.
Webhook Orchestration
Production-grade webhook handlers with idempotency keys for safe retries, payload validation that traverses nested objects, and structured error responses with doc URLs for debugging. Not a Zapier chain that silently fails.
System Integration
Connect CRMs, ERPs, and internal databases through a typed middleware layer. Each integration gets its own route class with dependency injection, Zod schema validation on every request, and automated OpenAPI spec generation.
REST & GraphQL APIs
Versioned APIs with header-based versioning, JWT + API key authentication, tiered rate limiting per endpoint, and request tracing with unique IDs. Every response follows a consistent envelope format with proper error codes.
Legacy System Wrappers
Modern typed API layers over legacy databases and SOAP services. We abstract the old system behind clean interfaces so your team gets predictable REST endpoints while the legacy system stays untouched.
Data Pipeline APIs
ETL endpoints that ingest documents (PDF, XLSX, DOCX), extract structured data, and route it between systems. Chunked processing for large files, with queue management and dead letter handling for failed operations.
Zapier/Make Migration
Rebuild no-code workflows as typed services when you hit scaling limits. Replace task-based pricing with flat-rate hosting, sequential steps with parallel execution, and silent failures with exponential backoff retry logic.
Our Stack
How we build it
API Layer
- →Express or FastAPI with TypeScript/Python, auto-generated OpenAPI specs
- →Zod schema validation on every request and response body
- →JWT + API key authentication, tiered rate limiting per endpoint
- →Header-based API versioning so client integrations never break
- →Idempotency keys on mutating endpoints for safe retries
Middleware Stack
- →Security headers (Helmet), CORS, payload size validation
- →Request ID tracing for end-to-end debugging across services
- →Runtime OpenAPI validation catches contract violations before they hit production
- →Structured error handler as the final middleware: every error gets a type, code, message, and doc URL
Infrastructure
- →Docker containerization deployed to cloud platforms (DigitalOcean, AWS, or your VPS)
- →PostgreSQL via Supabase for persistent storage, Row Level Security for data isolation
- →Redis for production rate limiting, caching, and queue management across instances
- →Sentry for error tracking, health/readiness endpoints for uptime monitoring
Testing & Quality
Every handler gets a corresponding integration test that runs against a real database. We use contract testing to verify API responses match the OpenAPI spec, validation testers that fuzz endpoints with edge cases (prototype pollution, XSS payloads, SQL injection, oversized payloads), and database seeders for reproducible test data. Pre-commit hooks block code that does not pass lint and build checks.
Is This Right For You?
Ideal client profile
Custom API development is the right fit if you:
- →Hit Zapier or Make limits (execution timeouts, task caps, two-step chains)
- →Need to sync data between 3+ systems in real time
- →Require error handling that actually recovers, not just retries
- →Pay more than $200/month in no-code platform fees
- →Have legacy systems that need modern API access
- →Need audit logs and compliance-ready integration pipelines
Flexible Engagement
Every integration is scoped to your systems, volume, and reliability requirements. We offer both project-based builds and monthly retainers for ongoing support and expansion. Book a discovery call and we will scope it together.
Ready to replace your no-code chains?
Book a discovery call. We will map your current integrations, identify failure points, and scope a production-grade replacement.
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