Sebastián Balay is a seasoned full-stack software engineer and leader with 11+ years building high-scale web and mobile experiences from Valencia, Spain. He blends hands-on expertise in Node.js, Ruby on Rails, React and React Native with proven tech leadership—designing architectures, estimating projects, hiring and mentoring teams. At Shopify he helped evolve the React Native codebase behind a mobile app with 20M+ MAU and contributed performance-focused improvements to notable open-source work like the restyle library. Previously he scaled engineering organizations at Wolox as Director of Technology and led platform rewrites and design systems at startups like Qasa. Comfortable alternating between coding and stakeholder-facing responsibilities, he prioritizes quality, maintainability and measurable performance gains. Colleagues describe him as a pragmatic architect who still digs into type-level front-end improvements and test robustness to drive real-world impact.
11 years of coding experience
12 years of employment as a software developer
Master of Engineering - MEng Computer Science, Master of Engineering - MEng Computer Science at UTN FRBA
A type-enforced system for building UI components in React Native with TypeScript.
Role in this project:
Front-end Developer
Contributions:2 releases, 8 reviews, 21 commits in 4 months
Contributions summary:Sebastián primarily focused on enhancing the `restyle` library's functionality and performance. They made changes to the type definitions, allowing for more flexible use of spacing properties. Furthermore, they optimized the `useRestyle` hook to improve performance by reducing redundant calculations and memoizing key values. Finally, the user updated the test suite to include the dimensions mock, providing more robust testing of the components built using restyle.
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