Daniel Y.
Senior Frontend Developer
Experience
Jan 2024 - Dec 2025
2 yearsSenior Frontend Developer
node.energy
- Significant enhancement of the B2B React SPA software 'opti.node' for commercial operations management for renewable energy plant operators
- Introduction of market-unique features, leading to a significant increase in revenue
- Extensive automated tests within Storybook
- Implementation of a UI library to improve developer experience and speed up feature development by about 40%
- Clear presentation of complex commercial and legal topics through intuitive UX and UI
- UX consulting to reduce essential interaction flows by 75%
- Technologies: React, TypeScript, TanStack Query, OpenAPI, Storybook, Mantine UI, HTML5, CSS3 (SCSS), Jest, React Testing Library, Git, CI/CD, Scrum, GitHub Copilot, technical documentation, UX
Oct 2023 - Dec 2023
3 monthsSenior Frontend Developer
B.Braun
- Time-critical development of an MVP with Angular for health care management software
- Delivered on time for the client presentation
- Compliance with all technical requirements and code standards within a SAFe process
- Technologies: Angular, TypeScript, RxJs, HTML5, CSS3 (SCSS), Material Design, Responsive Design, Nx (Monorepo), Jest, Git, CI/CD, SAFe, Scrum, GitHub Copilot
Jan 2023 - May 2023
5 monthsSenior Frontend Developer
porta Möbel Onlineshop
- Relaunched the online shop with Next.js 13 and React Server Components in an Nx monorepo setup
- Implemented new features and optimized the component library for scalable use across multiple brands
- Enabled fast design reviews via Storybook
- Built an automated testing system
- Ensured accessibility on both technical and UX levels
- Technologies: React, Next.js, TypeScript, HTML5, CSS Modules, Responsive Design, Atomic Design, Nx (Monorepo), Jest, React Testing Library, Test-Driven Development (TDD), Playwright (E2E), Cucumber, Storybook, accessibility (WCAG), FormatJS (i18n), Git, CI/CD, Scrum
Feb 2022 - Sep 2022
8 monthsLead Frontend Developer
BMW Alphabet
- Lead developer for the international relaunch of BMW's leasing brand as a React application in a headless architecture
- Led the team and onboarded two team members
- Developed a modular component library for flexible and consistent use
- UX consulting to optimize components for faster developer experience and meet time and budget requirements
- Transparent presentation of components via Storybook
- Built an automated testing system for functional unit and component tests as well as visual regression tests
- Technologies: React, Next.js, TypeScript, Headless CMS (Drupal), HTML5, CSS-in-JS, Responsive Design, Atomic Design, Storybook, Jest, accessibility (WCAG), Google Maps API, Git, CI/CD, team leadership, software architecture, technical documentation, UX
Sep 2020 - Dec 2021
1 year 4 monthsSenior Frontend Developer
MediaMarktSaturn Retail Group
- Developed a new platform for online sales of individual items and clearance stock from all stores in Germany
- Increased revenue by significantly extending reach beyond local catchment areas
- Created specialized marketing and landing pages as well as a React component library
- Overview of designs and UX components via Storybook
- Technologies: React, Next.js, JavaScript, HTML5, CSS-in-JS, Responsive Design, GraphQL, Contentful, Twig, Storybook, accessibility (WCAG), SEO, Git, Scrum
Nov 2017 - Apr 2020
2 years 6 monthsSenior Frontend Developer
WAGO Verbindungstechnik
- Iterative introduction of Vue.js components into an existing legacy JS/jQuery codebase, reducing load times in critical interaction paths by 40%
- UX consulting for faster iteration of complex features and interaction flows
- Internationalization of a hybrid content and shop website with a multilingual template interface
- Integration of the frontend into SAP Hybris / SAP Commerce environment
- Requirements management in distributed teams, increasing feature development speed by approx. 20%
- Optimization of development workflows and introduction of Git Flow
- Technologies: Vue.js, Vuex, jQuery, JavaScript, HTML5, CSS3 (LESS), Responsive Design, Prototyping, SAP Hybris (Frontend integration), Accessibility (WCAG), SEO, Git, Scrum, Kanban, Technical documentation, UX
Apr 2017 - Nov 2017
8 monthsSenior Frontend Developer
medion GmbH
- Implementation of a shop frontend for digital content of the brands "Aldi" and "Hofer"
- Development of dynamic jQuery components to extend shop features
- Integration into SAP Hybris environment
- Technologies: jQuery, JavaScript, Bootstrap, HTML5, CSS3 (LESS), Responsive Design, SAP Hybris (Frontend integration), Accessibility (WCAG), SEO, Git, Agile
Nov 2016 - Mar 2017
5 monthsSenior Frontend Developer
Deutsche See
- Shop relaunch for the wholesale and retail seafood retailer
- Creation of a dedicated Shopware 5 theme
- Development of dynamic template and content modules
- Use of Lighthouse for performance analysis and optimization
- Technologies: jQuery, JavaScript, HTML5, CSS3 (LESS), Shopware, Smarty, Accessibility (WCAG), SEO, Git, Scrum
Sep 2016 - Oct 2016
2 monthsSenior Frontend Developer
Die Techniker
- Implementation of a scrollytelling campaign with complex 3D animations tied to scroll movements
- Synchronization of pre-rendered videos, scroll events, and animated frontend elements in the browser
- Development of dedicated jQuery components to control all elements
- Technologies: jQuery, JavaScript, HTML5, CSS3 (SCSS), Responsive Design, Mobile-first development, Twig, SVG sprites, Visual storytelling, Asset pipeline, Git, Performance optimization
Aug 2014 - Aug 2016
2 years 1 monthSenior Frontend Developer
Der Spiegel
- Switching of the video players on the "Spiegel Online" and "Manager Magazin Online" portals
- Requirements analysis for possible video players for video-on-demand and live streams
- Integration of advertising systems into videos using VAST
- Technologies: jQuery, JavaScript, HTML5, CSS3 (LESS), Responsive Design, Mobile-first development, SEO, Git, Subversion, Requirements analysis, Performance optimization, Technical documentation, Prototyping
Summary
As a Senior/Lead Frontend Developer with 24 years of professional experience and deep JavaScript expertise, I craft React/TypeScript frontends with outstanding UX, high accessibility, and a clear focus on measurable business value. I have transformed complex B2B and e-commerce projects (e.g., node.energy, porta, BMW Alphabet, MediaMarktSaturn) using component-driven development with Storybook, test automation (Jest, Playwright), and modern state/API solutions (TanStack Query, GraphQL, OpenAPI) to shorten time-to-market and boost developer productivity. In agile environments (Scrum/SAFe), I deliver high-performance, maintainable solutions on time and within budget that combine technical excellence with immediate business impact.
Languages
German
NativeEnglish
AdvancedJapanese
ElementaryEducation
FH Wedel
Diploma in Media Informatics (FH) · Media Informatics · Wedel, Germany
Certifications & licenses
Professional liability insurance
exali AG / Markel Insurance
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