Denn Ro

Senior Full-Stack Engineer with 9+ years of experience architecting high-performance web and mobile applications across Europe, LATAM, and the US. Deeply specialized in TypeScript/JavaScript (Vue.js 3, React, Node.js) and cross-platform mobile ecosystems (Flutter). Actively scaling technical expertise into AI Product Engineering, combining a strong software architecture background with Python, FastAPI, and LangChain frameworks to build structured, validated, and production-ready AI applications.

Native

Spanish speaker with professional working proficiency in English (B2).

Senior Full-Stack & AI Engineer at Independent Contractor / Freelance (2025-01 – Present)

• Architecting and shipping full-stack mobile products using Flutter, Supabase, and AWS, ensuring optimal cross-platform state management.
• Developing and prototyping AI-driven workflows by implementing Python, FastAPI, and LangChain to build functional LLM integrations and intelligent backend services.
• Leveraging Pydantic for Structured Outputs, enforcing strict data validation schema patterns on LLM responses to guarantee reliable JSON payloads for frontend rendering.
• Building high-fidelity interactive MVPs using Streamlit to rapidly validate product specifications, interface ergonomics, and data pipelines.

Frontend Developer at CryptoLeague™ (2022-08 – 2025-01)

Led the frontend architecture and user interface for a high-traffic financial platform, operating within an international agile team communicating exclusively in English.

• Spearheaded the systemic migration from Vue 2 to Vue 3 (Composition API & Custom Composables), reducing client-side technical debt and enhancing overall application runtime efficiency.
• Implemented automated testing workflows by introducing Vitest, significantly raising code test coverage and accelerating CI/CD deployment cycles.
• Designed and maintained a proprietary library of reusable UI components.
• Integrated scalable GraphQL data ingestion layers.

Frontend Developer at UltraGrupo (2020-09 – 2022-08)

Developed web and mobile applications for the banking sector, automating high-volume credit management processes and secure financial transactions.

• Built and optimized responsive consumer-facing web architectures using React and cross-platform mobile codebases via React Native.
• Containerized cross-functional engineering workflows using Docker, ensuring absolute environment parity between staging and production.

Full-Stack Developer at TUATARA Aplicacions TIC SL (2016-01 – 2020-09)

Managed the full software development lifecycle (SDLC) for diverse enterprise clients, overseeing structural architecture, database design, and deployments.

• Development with PHP and CodeIgniter, applying the MVC architecture pattern.
• Engineered modular backend systems using PHP and CodeIgniter, ensuring code reliability through strict MVC design patterns.

Web Developer at Grupo ALVIC (2015-10 – 2016-04)

• Maintained corporate web and administrative modular extensions while handling PostgreSQL database.

Higher National Diploma in Multiplatform Application Development – La Salle Manlleu

Systems Engineering – Facultad de Ingeniería Nacional