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Skills

  • Node.js
  • API Development
  • Artificial Intelligence
  • Back End Development
  • Front End Development
  • JavaScript
  • LangChain
  • Mern Stack
  • Python
  • Rag
  • AI Chatbot Development
  • API Integration
  • Chatbots
  • ChatGPT
  • Document Processing

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Services

  • AI Chatbot Development

    $20/hr Starting at $150 Ongoing

    Dedicated Resource

    I build custom AI Chatbots for websites, e-commerce stores, customer support, internal tools, and knowledge-base systems. I can create context-aware chatbot workflows using LLMs, RAG, LangChain, APIs,...

    AI Chatbot DevelopmentAPI DevelopmentAPI IntegrationArtificial IntelligenceBack End Development
  • RAG/Document AI Chat System

    $25/hr Starting at $300 Ongoing

    Dedicated Resource

    I develop RAG-based document chat systems that allow users to ask questions from PDFs, documents, websites, FAQs, or internal knowledge bases. I can build the full workflow, including document processing,...

    AI Chatbot DevelopmentAPI DevelopmentAPI IntegrationArtificial IntelligenceBack End Development

About

AI Engineer & MERN Stack Developer | LLM, RAG, Chatbots, APIs

Hi, I'm Guillermo Lopez - a Full-Stack AI Developer specializing in web and mobile application development, OpenAI API integration, machine learning models, AI chatbots, automation systems, and business-ready software solutions.

I help businesses build practical AI-powered digital products from idea to working application.
I can create responsive websites, mobile-friendly web apps, dashboards, backend APIs, ChatGPT-style assistants, customer support chatbots, document Q&A systems, predictive machine learning models, and workflow automation tools.

My strength is combining AI engineering with full-stack development.
That means I can build the frontend interface, backend logic, database connection, API integration, AI workflow, and clean delivery structure in one complete solution.

- What I can help with:
✅OpenAI API integration for websites and apps
✅AI chatbot and assistant development
✅Machine Learning prediction models
✅Web and mobile-friendly application development
✅React, Node.js, Next.js, Python, FastAPI, and MERN stack apps
✅Backend API development and 3rd-party integrations
✅Dashboard UI, admin panels, and business portals
✅PDF/document AI and RAG-based Q&A systems
✅Workflow automation and AI business tools
✅Responsive design for desktop, tablet, and mobile
✅Clean source code, testing, and setup documentation

My process is simple and professional.
I review your goal, plan the system, build the frontend and backend, connect APIs or AI features, test carefully, and deliver clean source code with clear instructions.

If you need a developer who can build AI-powered web/mobile applications, OpenAI integrations, chatbots, Machine Learning models, or full-stack business platforms, I can help you turn your idea into a working solution.