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Marcos Prieto SierraMP

Marcos Prieto Sierra

Senior Software Engineer

€400/day
León, ES
15+ years

Average response time: 1 hour

Freelancer profile translated to English.
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About Marcos

React and TypeScript specialist focused on performance, architecture, and refactoring of complex applications. Experience leading migrations from AngularJS and resolving bottlenecks in large apps. I combine best practices, testing, and a pragmatic approach to deliver robust solutions.
  • Spanish

    Native or bilingual

  • English

    Fluent

  • Dutch

    Basic

Remote only
Primarily works remotely

Experience

  • Freelance
    Senior Frontend Engineer
    TRANSPORTATION
    December 2025 - Today (6 months)
    Project about tolls and road management systems in Europe. Developing a new application module using React and TypeScript, focusing on clean architecture and maintainable code.

    Improved testing strategy by introducing unit tests in the application, and Storybook for component-driven development.
    React.js Typescript AI Automation Monorepo
  • Exadel
    Senior Software Engineer
    February 2024 - November 2025 (1 year and 9 months)
    Led the migration of a large enterprise application (~200 modules/screens) from Angular.js to React, designing the full migration architecture (strategy, tooling, best practices) adopted by multiple teams. Introduced a micro-frontend architecture using Module Federation, enabling independently deployable vertical slices and long-term scalability. Mentored a team of 15 developers in modern React, architecture, and efficient workflows Built a shared React component library used across several internal projects.
  • RepeatMD
    Senior Fullstack Software Engineer
    May 2023 - December 2023 (7 months)
    Delivered key frontend and backend features for a private-label application used by aesthetic clinics in the USA. Improved code quality by adding missing tests, resulting in a more reliable and maintainable codebase.

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