Rafael G.

Senior Full-stack Web Developer

Nix • Full-time

Oct 2025 - Jan 2026 • 3 mos

Project: Internal AI Learning Platform - Engineered a full-stack AI learning platform using React.js and Convex, enabling 300+ employees to navigate node-based resource "paths" and real-time updates across the learning graph through end-to-end data synchronization. - Developed a dynamic, node-based UI using XY-Flow and Tanstack Router, reducing the administrative workflow for path creation to a single click. - Architected the High-Level Design (HLD) and relational data schemas, restructured the centralized repository, and refactored legacy code, integrating LLM APIs to generate interactive quizzes from raw text-based documentation automatically. Project: MCP-based AI Integration Layer: - Engineered an AI orchestration layer using Nest.js and MCP, reducing task execution time by 96%, from 5 minutes to under 10 seconds, for 3 critical workflows. - Architected a custom MCP server to expose 3 specialized tools across 2 disparate data sources, enabling Gemini and Anthropic models to perform real-time retrieval. - Implemented a unified host and client architecture using the @modelcontextprotocol/sdk to gain granular control over multi-LLM tool-calling execution, manage tool registration and context sharing, increasing architectural flexibility across multi-LLM integrations.

Senior Front-end Developer

Playtopia • Freelance

May 2025 - Aug 2025 • 3 mos

- Led the end-to-end development of a cross-platform (iOS/Android) MVP using React Native and Expo, onboarding 1,000+ users within 3 months, and providing high-performance data synchronization for complex subscription and class-booking workflows with Zustand, Axios, and Stripe. - Built an atomic design system and overhauled user flows to resolve critical UX gaps, accelerating subsequent UI development velocity by 42%. - Implemented schema validation with Zod, resulting in an 81% reduction in runtime errors and a 70% decrease in bug discovery time.

Freelance Full-Stack Developer

CarValue • Freelance

May 2025 - Jul 2025 • 2 mos

- Developed a robust session-based WordPress comparison plugin for a car marketplace, using PHP and WordPress Core functions, to deliver a persistent comparison tool with 100% retention of comparison data across page reloads, for 100+ monthly visitors. - Architected an extensible data schema to manage and display 20+ vehicle attributes, enabling rapid integration of new models without structural changes.