Marc – React, Typescript, Node.js

It's an app that teaches you to speak English by having voice message conversations with chatbots in various common situations.

• Developed the entire product stack end-to-end, from back-end services to real-time front-end interfaces.
• Implemented Generative AI & Speech Intelligence for natural, engaging conversations.
• Built real-time conversation analysis systems to provide actionable coaching feedback.
• Integrated Large Language Models (LLMs) and Speech-to-Text for accurate, AI-driven language interactions.
• Ensured privacy, security, and responsible AI practices, maintaining user trust and compliance.

It's a known Spanish real estate company.

• Designed, developed, and maintained front-end and back-end applications supporting the company’s core business operations.
• Contributed to the migration and refactoring of legacy systems into modern, maintainable, and scalable architectures.
• Built and enhanced internal platforms that improve customer experience and operational efficiency across multiple business areas.
• Implemented data integrations, APIs, and analytics-ready solutions to support reporting and informed decision-making.
• Collaborated on building secure, reliable, and scalable systems capable of supporting national and international growth.
• Worked closely with engineers, product managers, and other stakeholders to deliver high-quality solutions and ensure technical alignment.

It's a platform that creates, experiments with, and optimizes online campaigns to help companies and brands grow, resulting in more visitors, high-quality leads, and strong revenue.

• Built and maintained both front-end and back-end systems, ensuring seamless functionality and user experience.
• Collaborated on designing scalable and robust systems aligned with the company’s product vision.
• Worked closely with cross-functional teams during sprint planning, code reviews, and release cycles to deliver high-quality products on time.

Worked as a freelance engineer on 20+ projects, primarily with early-stage startups, helping founders turn ideas into reliable, production-ready products.

• Built full-stack web applications from scratch (back-end services, front-end interfaces, APIs).
• Designed scalable system architectures suited for fast-growing startups.
• Developed real-time features such as chat, live updates, and interactive user experiences.
• Turned early concepts and rough requirements into working products and MVPs.
• Improved performance, stability, and maintainability in existing codebases.
• Worked directly with founders and small teams to align technical decisions with business goals.
• Implemented security, privacy, and best engineering practices in production environments.