API Development

APIs your partners actually enjoy using

Well-versioned, well-documented REST or GraphQL APIs with auth, rate limiting, and webhooks. Built to be consumed by partners and customers — not only your own frontend.

Why work with me

A public API is a contract. I treat it that way — versioned cleanly, documented from day one, monitored, and designed so that the SDK practically writes itself.

30+

Production APIs shipped

<50ms

p95 on cached endpoints

99.9%

Uptime across deployed APIs

100%

Routes documented in OpenAPI

Trusted by founders & teams in

FinTechSaaSB2BE-commerceAI startups

Start a conversation

Reply within 24 hours. No sales call required upfront.

Or email smitparekh02@gmail.com directly.

What you get

Everything included in every engagement

No upsells. No surprise change orders. One scope, one price.

REST or GraphQL — picked for you

Not religion. REST for resource-shaped data and CDN cacheability. GraphQL when clients need flexible shapes and there's a real schema team.

OpenAPI / GraphQL schema

Generated docs that stay accurate. Type-safe clients for TypeScript, Python, Go via openapi-typescript or codegen. Postman collection on request.

Auth that scales beyond your frontend

API keys with rotation, OAuth 2.0 with PKCE, JWT with refresh, mTLS for partner integrations. Scoped permissions per token.

Rate limiting + quotas

Per-key, per-IP, per-endpoint limits with Redis. Quota dashboards your customers can self-serve. Burst tolerance + 429 with Retry-After done right.

Webhooks with retry & signing

HMAC-signed payloads, exponential backoff with jitter, dead-letter for failures, replay endpoint, idempotency keys on inbound.

Usage analytics & SLOs

Per-customer usage dashboards, p95/p99 latency tracking, error budget alerting. Sales can see who's hitting their limits.

Tech stack

The tools I actually use in production

Modern, battle-tested, and chosen for fit — not hype.

REST

  • NestJS
  • Fastify
  • OpenAPI
  • Zod

GraphQL

  • Apollo Server
  • Pothos
  • DataLoader
  • Mercurius

Auth

  • JWT
  • OAuth 2.0
  • Supabase Auth
  • Auth0

Infra

  • Redis
  • Kong / Tyk
  • Cloudflare
  • AWS API Gateway
Process

How we'll work together

Predictable, written-down, no surprises.

  1. 01

    Design first

    Endpoints, resources, errors, pagination, versioning strategy — all written in OpenAPI before code.

  2. 02

    Reference implementation

    Build a thin slice end-to-end: auth, one resource, full docs, one SDK. Validates the design with a real consumer.

  3. 03

    Build the surface

    Fan out the rest of the endpoints. Contract tests against the schema run on every PR.

  4. 04

    Launch & monitor

    Public docs site, sandbox keys, status page, and webhook test tool — the things partners actually expect.

Engagement models

Pricing that matches the work

Starting prices. Final quote in writing after a 30-minute scoping call.

Internal API

Backend for your own frontend

$3,000starting

  • 10–20 endpoints
  • JWT auth, OpenAPI docs
  • Tests, CI, deploy
Start with Internal API
Most popular

Public API

APIs your customers consume

$8,500starting

  • API keys, quotas, rate limiting
  • Webhooks + SDK
  • Public docs site + sandbox
  • Status page + monitoring
Start with Public API

Retainer

Long-term API evolution

$2,500/mostarting

  • New endpoints, deprecations
  • SDK maintenance
  • On-call coverage
Start with Retainer
FAQ

Questions I get asked first

REST or GraphQL?+

REST for partner-facing APIs (CDN-cacheable, simple integration). GraphQL when clients need to compose responses and there's a schema team. I'll recommend based on your actual consumers, not preference.

Do you build SDKs?+

Yes. TypeScript first, then Python, Go, and Ruby on request. Generated from OpenAPI so they stay in sync with the API.

How do you version an API?+

URL path versioning (/v1, /v2) with a documented deprecation window — typically 12 months — and a changelog endpoint for clients to subscribe to.

What about API gateway and edge?+

Kong, Tyk, or AWS API Gateway depending on your infra. Cloudflare Workers for edge auth and rate limiting where it makes sense.

Free 24-hour quote

Let's scope your project

Tell me what you're building. I'll reply with a written estimate within 24 hours — no sales call required.

Start a conversation

Reply within 24 hours. No sales call required upfront.

Or email smitparekh02@gmail.com directly.