Luis Fonseca

Full Stack Engineer with over 10 years of experience in high-performance systems. Specialist in the Node.js ecosystem, focusing on Full SDLC and scalable architectures. I adopt modern methodologies such as SDD (Spec-Driven Development) and use AI tools to optimize code review and team efficiency.

Proficient in Agile environments and collaborative remote teamwork, delivering quality features by managing both frontend and backend development using technologies such as TypeScript, NestJS, PHP, and Laravel. Committed to continuous learning and driving innovation to meet evolving business demands.

Full Stack Developer at 7Skin (2023-01 – Present)

Technical leadership in feature development with focus on system performance and code quality optimization.

• Technical leadership in feature development, resulting in a 15% improvement in system performance.
• Workflow optimization using AI to assist in code reviews and refactoring of legacy code.
• Implementation of Spec-Driven Development (SDD) to ensure robust API contracts and accurate documentation.
• Collaborated with cross-functional remote teams to deliver continuous integration and continuous delivery (CI/CD) pipelines using GitLab.
• Ensured code quality and maintainability by enforcing best practices, conducting code reviews, and integrating automated testing frameworks.

Full Stack Developer at YNB Agency - Grupo JAF (2020-01 – 2023-01)

Full Stack development with focus on backend optimization and sustainable development lifecycle management across complex projects.

• 30% reduction in server response time through critical backend optimization in Node.js.
• Full SDLC (Sustainable Development Lifecycle) management across multiple complex projects.
• Led technical leadership in feature development, achieving a 15% improvement in overall system performance.
• Enforced code quality and maintainability by establishing best practices and integrating automated testing frameworks.

Backend Developer at Imaginary Cloud (2019-01 – 2020-01)

Backend development with emphasis on scalability, high availability, and system architecture optimization.

• Ensured scalability and high availability of Node.js and MySQL production environment.
• Implemented MySQL NDB Cluster to eliminate single points of failure and improve data redundancy.
• Addressed technical debt and bug fixing.
• Translated client requirements into high-performance backend features.
• Enhanced overall system architecture.
• Designed and implemented RESTful APIs using Node.js and Express to support scalable backend services.
• Optimized database queries and indexes in MySQL to achieve a 30% reduction in server response times.
• Developed and maintained CI/CD pipelines using GitLab to enable seamless deployment processes.

Full Stack Developer at Venture Planet (2018-01 – 2019-01)

End-to-end development of e-commerce platform with complex business flows and Spec-Driven Development methodology.

• Led end-to-end development of Bioplatform for B2B and B2C markets.
• Managed project lifecycle from requirements definition to implementation.
• Implemented complex e-commerce flows and data management using PHP, Laravel, and MySQL.
• Optimized database queries and indexes in MySQL to achieve a 30% reduction in server response times.
• Applied Spec-Driven Development (SDD) to enforce robust API contracts and maintain synchronization between frontend and backend teams.

Full Stack & Mobile Developer at iDo Tech (2016-01 – 2018-01)

Native mobile development with focus on fleet management and WebAPI integration for real-time data synchronization.

• Developed native Java applications.
• Focused on robust integration with WebAPIs for real-time data synchronization.
• Implemented complex fleet management functionalities.
• Optimized performance and usability for mobile environment.
• Developed native Java applications with a focus on performance optimization and seamless user experience.
• Implemented complex fleet management functionalities within mobile apps to support business operations.
• Collaborated with cross-functional teams to ensure mobile applications meet functional and technical specifications.

Full Stack Developer at RCSoft (2015-01 – 2016-01)

Telecommunications sector development with focus on legacy system modernization and integration between VB6 and .NET implementations.

• Worked in Telecommunications sector on evolutionary maintenance and modernization of billing and ERP systems.
• Optimized and corrected functionalities in Litigation system.
• Acted as technological bridge between legacy VB6 modules and new .NET (C#) implementations.
• Developed WebAPIs to ensure data integrity and continuous integration of new modules.
• Preserved and improved complex business rules.

Web Developer at COMSOFTWEB (2010-01 – 2015-01)

Full development cycle of customized solutions integrated with enterprise management systems and WordPress platform.

• Responsible for entire development cycle of customized solutions integrated into Eticadata ERP system.
• Gathered client requirements and performed data modeling.
• Developed in C# and VB.NET.
• Created customized PHP plugins for WordPress.
• Ensured integration between web platforms and enterprise management systems.
• Developed automated testing scripts using tools like Jest and Selenium to ensure code quality.
• Monitored and optimized web application performance, resulting in improved load times and reduced server resource consumption.

Degree in Computer Engineering – Polytechnic Institute of Coimbra (2005-01 – 2008-01)