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Fiverr Pro
English
$
USD
I will develop a API or integrate into your app, integrate stripe
John
About this gig
I build clean, documented, production-grade APIs and I integrate third-party APIs so they work seamlessly in your application.
What I build:
RESTful APIs with FastAPI (Python) async, typed, blazing fast
Auto-generated OpenAPI/Swagger documentation
JWT authentication with refresh tokens and role-based access
Input validation with Pydantic every request validated, every error handled
Database layer with SQLAlchemy 2.0 (async) + Alembic migrations
Third-party integrations I've built:
Payment: Stripe, PayPal, Square
Email: SendGrid, Resend, Mailgun
Storage: AWS S3, Cloudflare R2, MinIO
Auth: Auth0, Firebase Auth, Google/GitHub OAuth
AI: OpenAI, Anthropic, Hugging Face
Maps: Google Maps, Mapbox
Messaging: Twilio, Discord webhooks
Every API I deliver includes:
OpenAPI/Swagger docs (interactive, testable)
Structured error responses with proper HTTP status codes
Request/response validation on every endpoint
Rate limiting and input sanitization
Docker containerization (Pro+)
Postman collection for testing
30 days bug-fix support
I don't write spaghetti endpoints. I build APIs that your frontend team will actually enjoy working with.
Get to know John
John
Developer
- FromUnited States
- Member sinceApr 2026
- Avg. response time1 hour
Languages
English, Spanish
Custom software, AI systems, and secure infrastructure
What I build:
• AI chatbots & voice agents (custom-trained models, not wrapper APIs)
• Full-stack web applications (Python/FastAPI, Next.js, React, Tailwind)
• Automation scripts & bots (Discord, scraping, data pipelines)
• Security audits & penetration testing (certified, Network Security+)
• Cloud infrastructure (Docker, nginx, PostgreSQL, Redis — hardened production deployments)
I run my own GPU cluster and train my own AI models. When I say "custom AI," I mean it, not a ChatGPT wrapper.
Fast delivery.
My Portfolio
Other Software Development Services I Offer
FAQ
What language/framework do you use?
Python 3.12 with FastAPI. It's the fastest Python web framework, natively async, auto-generates OpenAPI docs, and enforces type safety with Pydantic. If you need Node.js or Go instead, message me — I can accommodate.
Can you integrate with my existing frontend?
Yes. I'll build the API to match your frontend's needs — proper CORS config, the exact request/response shapes your app expects, and WebSocket support if you need real-time updates.
Do you write tests?
Yes. Production API tier and above includes unit tests (pytest) covering all endpoints, auth flows, and edge cases. I also include a Postman collection so you can manually test every endpoint.
Can you connect to my existing database?
Absolutely. I can work with PostgreSQL, MySQL, MongoDB, or SQLite. If you're starting fresh, I'll design the schema. If you have an existing database, I'll build the API layer on top of it.
What about API versioning?
I implement URL-based versioning (/v1/, /v2/) so you can evolve your API without breaking existing clients. Migration guides included for major version changes.
