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I will build or fix secure nodejs python fastapi backend apis
Gul Hassan
About this gig
Need a reliable developer to build, fix, or improve your backend API?
Im a Backend Developer specializing in Node.js, Express.js, Python, FastAPI, and Django. I have hands-on experience working on production applications and can help with both new backend development and existing projects.
What I can help you with:
REST API development and modification
API bugs, errors, and debugging
Authentication & authorization (JWT, OAuth, RBAC)
MongoDB & PostgreSQL database integration
Third-party API integrations and webhooks
CORS and backend security configuration
Backend feature development and updates
API validation and error handling
Asynchronous/background processing
WebSocket and real-time features
API testing and documentation
AI/LLM API integrations
I work with clean, secure, maintainable code and focus on understanding your requirements before implementation.
Please contact me before placing an order for complex or custom requirements so I can recommend the right package.
Get to know Gul Hassan
Gul Hassan
Full Stack Developer AI and Backend Engineer
- FromPakistan
- Member sinceAug 2026
Languages
English, Urdu
I am a Full Stack Developer and AI Engineer with 1+ year of professional experience building production ready web applications, REST APIs, backend systems, and AI powered solutions. My expertise includes Node.js, Express.js, Python, React.js, Laravel, MongoDB, PostgreSQL, and AWS. I have hands on experience with OpenAI APIs, RAG, semantic search, LLM applications, third party integrations, debugging, and deployment. I focus on clean, scalable code and delivering reliable solutions based on client requirements.
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Other Software Development Services I Offer
FAQ
What technologies do you work with?
I primarily work with Node.js, Express.js, Python, FastAPI, and Django, along with MongoDB and PostgreSQL.
Can you fix an existing backend or API?
Yes. I can troubleshoot API errors, backend bugs, authentication issues, database problems, CORS errors, and other backend-related issues.
Can you add new features to my existing backend?
Yes. I can add new API endpoints, authentication, database functionality, third-party integrations, webhooks, real-time features, and other backend functionality.
Can you integrate third-party APIs?
Yes. I can integrate services such as Google Calendar, payment APIs, communication APIs, AI APIs, OAuth providers, and other third-party services.
Do you work with authentication and security?
Yes. I can implement JWT authentication, authorization, RBAC, password security, CORS configuration, validation, and other backend security practices.
Can you build AI or RAG backend systems?
Yes. I can integrate OpenAI, Gemini, embeddings, vector search, RAG pipelines, and AI-powered APIs into your backend.
Will I receive the source code?
Yes. Source code is included according to the selected package.
Can you work with my existing codebase?
Yes. I can review your existing backend, understand the current architecture, and implement the required changes without unnecessarily rebuilding the project.
Can you handle custom requirements?
Yes. For complex requirements, please contact me before ordering so I can review the scope and provide the appropriate solution and pricing.
