Ej Sinfuego
Full‑stack developer focused on TypeScript/React and backend APIs. I ship production features end‑to‑end and care about performance, reliability, UX, and DX.
Shipping features for Atlas (RedwoodJS monorepo) and improving UX & DX.
Projects
LangChain
OpenAI
Groq
Next.js
TypeScript
RAG
RAG-powered chatbot integrated into this portfolio, built with LangChain, OpenAI embeddings, and Groq. Features file upload, document processing, and intelligent question answering based on uploaded content.
Details
Problem
Need an intelligent assistant that can answer questions based on personal documents and knowledge base.
Key actions
- Implemented RAG pipeline with document chunking and vector embeddings
- Created file upload system supporting PDF, TXT, MD, and JS files
- Built responsive chat interface with real-time messaging
- Integrated OpenAI embeddings and Groq chat model for cost-effective AI
Results
- Intelligent document-based Q&A system
- Seamless integration with portfolio design
- Cost-effective AI using Groq's fast inference
RedwoodJS
Prisma
GraphQL
ReactJS
TailwindCSS
VPS
Atlas is a RedwoodJS monorepo for a membership/education platform, featuring a Prisma/GraphQL API and React web app to manage cohorts, courses, accountability groups, affiliates, and payments, with supporting data-sync scripts, VPS deployment, and strong testing/docs/tooling.
Details
Problem
The Freelace Movement Tribe needs a platform to manage their courses, cohorts, accountability groups, affiliates, and payments.
Key Roles
- Helped the team to plan and design the architecture of the platform
- Executed the migration of the server from Vercel to VPS for scalability and reliability.
- Optimized database queries and refactor codebase to follow coding standards and best practices.
- Architected SSO for the application to improve security and user experience.
- Implemented a data-sync script to sync the data from the API to the database.
- Implemented a CI/CD pipeline to automate the deployment of the platform.
Spring-Boot
ReactJS
NextJS
ExpressJS
Heroku
MedusaJS
Bella’s Bakery UI is a modern e-commerce frontend for a bakery built with Next.js (App Router) and TypeScript, integrating Medusa for core commerce. It offers product browsing/search, a real-time cart, secure Stripe checkout, order management, and a responsive SCSS-based UI. The architecture follows SOLID and atomic design, using React Context with custom hooks and TanStack Query over a service/repository layer, with strong quality tooling (Jest/RTL/Playwright, ESLint/Prettier/Husky) and comprehensive in-repo docs.
Details
Problem
The bakery needed a modern online presence to expand reach and streamline operations.
Key actions
- Built storefront with product catalog, cart/checkout, and inventory management
- Created admin dashboard for product management, order tracking, and inventory control
- Integrated payment gateway for secure transactions
- Deployed to Heroku for scalability and reliability
Results
- Increased online sales by 30%
- Reduced manual order processing time by 50%
Electron
ReactJS
TailwindCSS
Native sticky notes app that stays on top for quick capture.
Details
Problem
I needed a lightweight notes tool that always stays visible across apps.
Key actions
- Electron shell with React UI and Tailwind styling
- Window always-on-top and transparency for minimal distraction
- Local persistence and keyboard shortcuts for quick capture
Results
- Faster task capture; app launches in under a second
- Daily personal use; iterating based on small usability wins
Laravel
MySQL
TailwindCSS
VPS
University theses and academic works index with search and RBAC.
Details
Problem
Students couldn’t easily find prior theses; admins lacked content workflow.
Key actions
- Designed schema for works, authors, and access levels
- Implemented role‑based access for submission and review
- Deployed to VPS with backups and HTTPS
Results
- Search and browse reduce manual librarian lookups
- Cleaner submission workflow for faculty reviewers
Godot
GDScript
Blender
Quest‑based 3D horror game set on a campus; team collaboration.
Details
Problem
Translate level design into interactive gameplay with atmosphere.
Key actions
- Integrated 3D assets and scripted quest triggers in Godot
- Optimized scenes for performance on mid‑range hardware
Results
- Playable web build; stable 60 FPS on typical laptops
Laravel
InertiaJS
PHP
CLI to scaffold InertiaJS page components for Laravel projects.
Details
Problem
Repetitive page setup slowed delivery across Laravel + Inertia projects.
Key actions
- Scaffolded component structure and wiring via CLI
- Added parameters for common variants and states
Results
- Cut page setup time from minutes to seconds
VB.Net
Desktop file organizer grouping by type/name patterns.
Details
Problem
Messy downloads folder; manual sorting was error‑prone.
Key actions
- Watched directory and moved files into typed folders
- Configurable rules for extensions and name prefixes
Results
- Clean downloads automatically; time saved weekly