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.

Experience

Driven Insurance

Current

Junior Full-Stack Developer (AI & Automation)

Remote2025 - Present

Contributing to the development of an AI Autodialer platform. Responsible for implementing frontend interfaces and backend logic based on technical specifications provided by the lead developer.

Achievements
  • AI Voice Integration

    Implemented the Vapi.ai SDK into the web application to enable voice capabilities for automated calls.

  • Backend Development

    Developed API endpoints and WebSocket handlers to manage call sessions and data transfer between the client and AI services.

  • Frontend Implementation

    Built reactive UI components for the real-time call monitoring dashboard and transcription logs using Next.js and TailwindCSS.

  • Feature Implementation

    Built the bulk-upload feature allowing users to import CSV lead lists, following the database schema design.

  • Prompt Engineering Support

    Updated and tested AI system prompts based on feedback to improve conversation flow and accuracy.

Next.jsReactVapi AIWebSocketsNode.jsPostgreSQLTailwindCSS

Junior Full-Stack Developer

Remote2024 - Present

Working on Atlas, a RedwoodJS monorepo for a membership/education platform. Building production features end-to-end with focus on performance, reliability, and developer experience.

Achievements
  • Infrastructure Migration

    Executed (with DevOps consultation) the migration from Vercel to a custom VPS (Virtual Private Server), resulting in significantly lower hosting costs and improved control over server resources.

  • Complex Business Logic Refactoring

    Engineered a critical platform pivot from a recurring subscription model to a perpetual licensing system. Refactored core payment gateways and database schemas under strict deadline constraints.

  • Security & Identity

    Architected a custom Single Sign-On (SSO) solution to unify user access across the community's ecosystem.

  • Performance Engineering

    Optimized Prisma database queries and implemented data-sync scripts, reducing API latency and ensuring real-time data consistency.

  • DevOps & Automation

    Established a CI/CD pipeline to automate testing and deployment, reducing manual errors during release cycles.

RedwoodJSPrismaGraphQLReactTypeScriptPostgreSQLVPSCI/CDSSORedisInngestTailwindCSS

Full-Stack Developer

Remote2024 - 2025

Built a modern e-commerce platform for a bakery using Next.js and MedusaJS. Delivered a complete online ordering system including a custom storefront, admin management, and secure payments.

Achievements
  • Storefront Development

    Developed the customer-facing UI including product catalogs, shopping cart functionality, and checkout flow using Next.js.

  • Admin Dashboard Implementation

    Implemented dashboard features for the client to manage inventory, track orders, and update product details easily.

  • Payment Integration

    Integrated Stripe API to handle secure checkout sessions and payment processing.

  • State Management

    Utilized TanStack Query for efficient data fetching and React Context for managing global cart state across the app.

  • Deployment & Configuration

    Deployed the Next.js frontend and Medusa backend to Heroku, configuring environment variables for production.

Next.jsReactTypeScriptMedusaJSStripeSCSSHerokuTanStack Query

Projects

ReactTailwind CSSReact Flow
Solo developer

Interactive code map of my projects, built with React, Tailwind CSS, and Framer Motion.

Details

Problem

Need a way to visualize my projects and code in a more interactive way.

Key actions

  • Implemented interactive code map with React, Tailwind CSS, and React Flow to visualize my projects and code in a more interactive way.

Results

  • Interactive code mind map
LangChainOpenAIGroqNext.jsTypeScriptRAG
Solo developer

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
RedwoodJSPrismaGraphQLReactJSTailwindCSSVPS
Full-stack developer

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-BootReactJSNextJSExpressJSHerokuMedusaJS
Full-stack developer

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%
ElectronReactJSTailwindCSS
Solo developer

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
LaravelMySQLTailwindCSSVPS
Full‑stack developer

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
GodotGDScriptBlender
Gameplay and integration

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
LaravelInertiaJSPHP
Tooling author

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
Solo developer

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

Community

GitHub Activity

 
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