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Senior Front-End Engineer (10+ yrs) in Berlin specializing in design systems, payment flows, and multi-market web applications for FinTech and e-commerce. Built and shipped a company-wide UI component library from scratch (@expatrio/mui-library, 23 Storybook-documented components), integrated Flywire payments and MangoPay SCA (PSD2), and launched heycar’s Polish SSR platform. I turn design systems into production-ready products and help modernize legacy codebases for maintainability, performance, and accessibility. Core stack: React, Next.js, TypeScript, with a strong focus on experimentation, analytics, and test-driven quality.…Senior Front-End Engineer (10+ yrs) in Berlin specializing in design systems, payment flows, and multi-market web applications for FinTech and e-commerce. Built and shipped a company-wide UI component library from scratch (@expatrio/mui-library, 23 Storybook-documented components), integrated Flywire payments and MangoPay SCA (PSD2), and launched heycar’s Polish SSR platform. I turn design systems into production-ready products and help modernize legacy codebases for maintainability, performance, and accessibility. Core stack: React, Next.js, TypeScript, with a strong focus on experimentation, analytics, and test-driven quality.

Mahmoud Zakaria

Front-End Developer, Web Developer, Software Engineer, +2

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Senior Front-End Engineer (10+ yrs) in Berlin specializing in design systems, payment flows, and multi-market web applications for FinTech and e-commerce. Built and shipped a company-wide UI component library from scratch (@expatrio/mui-library, 23 Storybook-documented components), integrated Flywire payments and MangoPay SCA (PSD2), and launched heycar’s Polish SSR platform. I turn design systems into production-ready products and help modernize legacy codebases for maintainability, performance, and accessibility. Core stack: React, Next.js, TypeScript, with a strong focus on experimentation, analytics, and test-driven quality.…Senior Front-End Engineer (10+ yrs) in Berlin specializing in design systems, payment flows, and multi-market web applications for FinTech and e-commerce. Built and shipped a company-wide UI component library from scratch (@expatrio/mui-library, 23 Storybook-documented components), integrated Flywire payments and MangoPay SCA (PSD2), and launched heycar’s Polish SSR platform. I turn design systems into production-ready products and help modernize legacy codebases for maintainability, performance, and accessibility. Core stack: React, Next.js, TypeScript, with a strong focus on experimentation, analytics, and test-driven quality.

Available to hire

Senior Front-End Engineer (10+ yrs) in Berlin specializing in design systems, payment flows, and multi-market web applications for FinTech and e-commerce. Built and shipped a company-wide UI component library from scratch (@expatrio/mui-library, 23 Storybook-documented components), integrated Flywire payments and MangoPay SCA (PSD2), and launched heycar’s Polish SSR platform.

I turn design systems into production-ready products and help modernize legacy codebases for maintainability, performance, and accessibility. Core stack: React, Next.js, TypeScript, with a strong focus on experimentation, analytics, and test-driven quality.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Intermediate

Beginner

Language

English

Fluent

Arabic

Fluent

German

Beginner

Work Experience

Senior Front-End Engineer at Expatrio GmbH

October 1, 2024 - Present

Designed, built, and published @expatrio/mui-library, a private npm design-system (Material-UI base, 23 Storybook-documented components) adopted across User Portal, admin Console, and Partner Portal. Built an end-to-end Flywire payment flow using the internal component library as its first full production validation. Integrated MangoPay Strong Customer Authentication (SCA/PSD2) into the banking activation flow to meet EU regulatory requirements. Led front-end execution for the Aion Bank → UniCredit rebrand across internal banking pages with zero UX regression. Instrumented product analytics with Amplitude (SDK + APIs) to support behavior analytics, A/B testing, and feature flagging across teams.

Senior Front-End Engineer at Heycar GmbH

May 1, 2021 - October 1, 2024

Launched heycar’s Polish market localized SSR application (Next.js, i18n, CSS-in-JS) to production readiness. Worked with the Spanish team on a high-traffic online platform for buying cars, using React/Next.js, TypeScript, styled-components, and headless CMSs (Contentful/Kontent.ai). Designed and delivered UI components, product features, refactors, and critical bug fixes. Developed/enhanced/refactored core UI components and business-critical features for an internal SPA backoffice. Rebuilt the cross-market rebuild of the main Heycar web platform upgrading to Next.js 13, CSS Modules, and GrowthBook for experimentation, improving performance and maintainability.

Front-End Engineer at Metatrust GmbH

February 1, 2020 - May 1, 2021

Developed core features of a global investment platform serving institutional investors with secure access to cross-border deal flows. Designed and delivered new features for a complex single-page application improving usability, performance, and scalability. Worked end-to-end with React, Node.js, and GraphQL in close collaboration with product, design, and backend teams. Refactored and modernized parts of a legacy codebase to reduce technical debt and improve maintainability. Resolved production issues proactively and supported platform stability. Participated in code reviews and architecture discussions to ensure high engineering standards and long-term platform health.

Front-End Engineer at Dunnhumby GmbH

April 1, 2018 - February 1, 2020

Joined the Component Library team of a large-scale customer data science platform contributing to a mission-critical design system used across multiple products. Developed and maintained reusable production-ready web components in the internal open-source library "Nessie-UI" using React. Joined an internal product team responsible for building cross-platform marketing tools enabling retailers to create, manage, and optimize their marketing campaigns. Improved navigation and usability of the store media platform using TypeScript, React, Redux, and Webpack. Delivered new features while ensuring stability, performance, and consistent design standards.

Front-End Engineer at Mondia GmbH

January 1, 2017 - April 1, 2018

Developed and maintained customer-facing UIs for Vodafone online game stores across Germany, Spain, and multiple African markets. Built/enhanced web interfaces for the O2 online gaming shop supporting high-traffic telecom environments. Played a key role in Vodafone DE/ES/Africa game stores rebranding initiatives ensuring consistent UX across markets. Implemented and optimized subscription plan flows enabling seamless user onboarding and monetization.

Front-End Engineer at Diva-lab

May 1, 2014 - January 1, 2017

Diva-lab was a web solutions startup where he started his career as a junior front-end engineer.