Senior Full‑Stack Engineer · React / Node.js · AI‑enabled apps · 🇨🇴🇺🇸 EN/ES

• 14+ years building high‑impact web & mobile products (React, React Native, Node.js, TypeScript).
• Bilingual English/Spanish. Based in Colombia (GMT‑5).
• Comfortable in product squads: discovery → delivery, CI/CD, testing, observability.
• US‑friendly contracting via my LLC, Parrot Apps (invoices in USD, time‑zone aligned).
• Current focus: Next.js, headless CMS, GraphQL/REST, AWS, and AI integrations (OpenAI, MCP servers, LLM tooling).

EN. Senior/Lead JavaScript engineer specialized in React and Node.js. I help teams ship fast, clean, and scalable frontends, with strong attention to DX, performance, and accessibility (WCAG). I’ve led migrations to headless architectures, created reusable design systems, and mentored devs in modern frontend practices.
ES. Ingeniero Senior/Lead JavaScript especializado en React y Node.js. Ayudo a equipos a entregar frontends escalables y performantes, con foco en DX, performance y accesibilidad. He liderado migraciones a headless, creado design systems reutilizables y acompañado a equipos en buenas prácticas modernas.

• Building AI‑augmented experiences (chat, assistants, content tools) with OpenAI, Ollama, and MCP server integrations.
• Headless front‑of‑site initiatives (Sitecore → Contentful / Next.js), content modeling, and multi‑locale strategies.
• Developer productivity: Storybook, testing (Jest/RTL/Cypress), CI/CD, and component libraries.

Frontend: React, Next.js, React Native, TypeScript, Redux/Context, HTML5, CSS/SASS, RTL, Cypress
Backend: Node.js/Express, GraphQL, REST, Python (basics), PHP
Cloud & DevOps: AWS (S3, ECS, Lambda, EC2), Docker, GitHub Actions/GitLab CI, Terraform (foundational)
Data: PostgreSQL, MySQL, Firebase
AI: OpenAI API, LLM‑driven features, Model Context Protocol (MCP) servers, embeddings, RAG basics

• Headless migration: Led feature development for a high‑traffic front‑of‑site migrating from Sitecore to Contentful + Next.js, including content models, Storybook stories, and soft‑deploy checks.
• Design system: Built a component library with accessibility & testing baked in (Storybook + RTL + visual tests), enabling faster delivery across squads.
• Performance: Achieved ~35% faster load times via code‑splitting, lazy loading, and caching strategies.
• Mobile: Released React Native apps with CI/CD (store release process, monitoring, OTA updates).

Want more detail? See my CV and LinkedIn or reach out for a portfolio walkthrough.

• 🧩 Dynaforms — Application designed to dynamically construct forms based on an array of objects describing each field.
• ⚡ Rovers UI — web application that provides information about the positions and image galleries of Mars rovers.
• 🤖 AI Playground — small demo integrating OpenAI and reactjs frontend.

• Product mindset: collaborate with PM/Design, write clear tickets, and push small, safe increments.
• Quality: testing pyramid, observability, and CI/CD gates.
• Collaboration: code reviews with empathy, mentoring, and documentation as a first‑class citizen.

• 📫 Email: contact@codejhon.com
• 💼 LinkedIn: /in/codejhon
• 🗓️ Book a call: Book a Call
• 🧾 Contracting via Parrot Apps LLC (US‑based) — easy vendor onboarding and invoicing.