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Hello, I’m Julio Sosa, a Senior Frontend Engineer with 6+ years of experience building, maintaining, and scaling user-facing web applications, primarily for e-commerce and CMS-driven platforms. I have a strong background in HTML, CSS, JavaScript, and modern frontend workflows, with hands-on experience in WordPress, Twig, PHP, React, and automated testing. I enjoy combining solid engineering practices with a design-aware mindset, enabling close collaboration with designers and delivering intuitive, high-quality user interfaces. I also bring a strong design sensibility and attention to detail, informed by a background in visual arts and multimedia.…Hello, I’m Julio Sosa, a Senior Frontend Engineer with 6+ years of experience building, maintaining, and scaling user-facing web applications, primarily for e-commerce and CMS-driven platforms. I have a strong background in HTML, CSS, JavaScript, and modern frontend workflows, with hands-on experience in WordPress, Twig, PHP, React, and automated testing. I enjoy combining solid engineering practices with a design-aware mindset, enabling close collaboration with designers and delivering intuitive, high-quality user interfaces. I also bring a strong design sensibility and attention to detail, informed by a background in visual arts and multimedia.

Julio Sosa

Front-End Developer, Web Developer, Designer, +3

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Hello, I’m Julio Sosa, a Senior Frontend Engineer with 6+ years of experience building, maintaining, and scaling user-facing web applications, primarily for e-commerce and CMS-driven platforms. I have a strong background in HTML, CSS, JavaScript, and modern frontend workflows, with hands-on experience in WordPress, Twig, PHP, React, and automated testing. I enjoy combining solid engineering practices with a design-aware mindset, enabling close collaboration with designers and delivering intuitive, high-quality user interfaces. I also bring a strong design sensibility and attention to detail, informed by a background in visual arts and multimedia.…Hello, I’m Julio Sosa, a Senior Frontend Engineer with 6+ years of experience building, maintaining, and scaling user-facing web applications, primarily for e-commerce and CMS-driven platforms. I have a strong background in HTML, CSS, JavaScript, and modern frontend workflows, with hands-on experience in WordPress, Twig, PHP, React, and automated testing. I enjoy combining solid engineering practices with a design-aware mindset, enabling close collaboration with designers and delivering intuitive, high-quality user interfaces. I also bring a strong design sensibility and attention to detail, informed by a background in visual arts and multimedia.

Available to hire

Hello, I’m Julio Sosa, a Senior Frontend Engineer with 6+ years of experience building, maintaining, and scaling user-facing web applications, primarily for e-commerce and CMS-driven platforms. I have a strong background in HTML, CSS, JavaScript, and modern frontend workflows, with hands-on experience in WordPress, Twig, PHP, React, and automated testing. I enjoy combining solid engineering practices with a design-aware mindset, enabling close collaboration with designers and delivering intuitive, high-quality user interfaces.
I also bring a strong design sensibility and attention to detail, informed by a background in visual arts and multimedia.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Intermediate

Language

Spanish; Castilian

Fluent

English

Advanced

French

Beginner

Catalan; Valencian

Beginner

Work Experience

Senior Frontend Software Engineer at Marbill Technologies

April 1, 2025 - September 5, 2025

Front-end development with HTML, CSS, Javascript, Twig and PHP frameworks for large scale e-commerce applications. Optimization and documentation of development processes. Automated QA testing for CI/CD Pipeline. 3rd Party API implementations to framework. Used Playwright and React.

Frontend Software Engineer at Cognizant Netcentric

August 1, 2022 - September 5, 2025

Front-end development in projects built on Adobe Experience Manager. Javascript codebase maintenance and Testing.

Frontend Developer & Designer at Metric Salad

March 1, 2021 - September 5, 2025

Translated designs to prototypes and websites for production using HTML, Sass, Javascript (and several libraries), Gulp, BEM, Git, and more. Created custom-made CSS/Sass frameworks for projects. Worked on frontend development with Wordpress, Ionic, Moodle, Angular, and React projects.

Designer at Mideo

June 1, 2017 - September 5, 2025

Internship at a start-up. Created layouts for the “Mideo” app’s web interface. Developed templates for Front-end. Designed and laid out electronic books in ePub format.

Frontend Software Engineer at Marbill Technologies

September 1, 2022 - April 1, 2025

Developed and maintained large-scale e-commerce frontends using HTML, CSS, JavaScript, Twig, and PHP. Supported multiple high-traffic e-commerce sites sharing a common technical architecture. Implemented scalable frontend patterns to separate content from logic, improving long-term maintainability and reuse across projects. Integrated and maintained third-party APIs within the existing framework, ensuring consistency and reliability across environments. Collaborated closely with backend developers, product owners, and stakeholders to deliver features aligned with both technical and business requirements.

Frontend Software Engineer at Cognizant Netcentric

September 1, 2021 - August 1, 2022

Frontend development for enterprise-level projects built on Adobe Experience Manager (AEM). Maintained and extended large JavaScript codebases, focusing on stability, readability, and long-term sustainability. contributed to testing and quality assurance processes within a structured, enterprise-scale development environment.

Frontend Developer & Designer at Metric Salad

November 1, 2018 - March 1, 2021

Translated visual designs into production-ready websites using HTML, Sass, and JavaScript, following BEM methodology and modular CSS principles. Designed and implemented custom CSS/Sass frameworks adapted to the needs of individual projects. Built reusable frontend components and layouts for multiple client-facing websites. Worked across a variety of platforms and technologies, including WordPress, Ionic, Moodle, Angular, and React. Collaborated closely with designers, bridging design intent and technical implementation.