Stefan Dietz

Frontend Developer – Sports Event and City Portal Projects

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Neubiberg, Germany

Experience

Mar 2024 - Jun 2025
1 year 4 months

Frontend Developer – Sports Event and City Portal Projects

München Betriebs GmbH

  • Developed an accessible, responsive website based on Figma designs for a major sports event following WCAG, BITV and EN 301 549
  • Planned and set up the toolstack with Vite, Playwright, Docker and GitLab CI
  • Contributed to two existing projects (Vue.js & Nuxt), focusing on bug fixes, accessibility audits and adding new features
  • Collaborated with design and QA to consistently implement accessible UI patterns
  • Advised on improving existing frontend architectures regarding accessibility, performance and maintainability
Jul 2023 - Present
2 years 7 months

Lead Developer for the Accessible Component Library “KoliBri”

ITZBund

  • Developed and maintained accessible web components with Stencil and TypeScript according to WCAG, BITV and EN 301 549
  • Refactored and optimized APIs to improve developer experience and reusability
  • Built and maintained cross-component theming systems based on design specifications (Design Tokens, Custom Properties)
  • Evolved and integrated internal React applications using KoliBri
  • Designed and developed a reusable framework for visual regression testing of components and themes
  • Set up a monorepo with pnpm workspaces to optimize build and development processes
  • Established CI/CD workflows with GitHub Actions and implemented automated test and release pipelines
  • Introduced Playwright as the E2E testing standard in the project
  • Provided technical leadership for the development team, including mentoring, code reviews and architectural decisions
Sep 2016 - Jun 2023
6 years 10 months
Munich, Germany

Deputy Frontend Team Lead

CHECK24 Vergleichsportal Baufinanzierung GmbH

  • Developed and scaled internal and customer-facing web applications with Vue.js, Nuxt, TypeScript and AngularJS, as well as Java and Spring Boot in the backend
  • Provided technical leadership for feature teams and acted as deputy team lead, focusing on quality assurance, mentoring and improving team processes
  • Responsible for architecture within the frontend team: making decisions on technologies, modularization and shared standards to ensure a sustainable codebase
  • Led a new website project (Node.js, Express, Nuxt) with a focus on performance – reduced load times by about 90% through targeted code-splitting, lazy loading and optimized caching
  • Built a universal build and test system with Webpack, Jest and npm scripts for all frontend projects
  • Optimized performance of core pages to improve load times and Core Web Vitals
  • Developed a Node.js microservice with Puppeteer for automated PDF generation
  • Enhanced an internal design system including new components and integration into multiple applications
  • Introduced and maintained CI/CD pipelines with Jenkins in close collaboration with DevOps and backend (Java/Spring)
  • Developed a dashboard to monitor npm dependencies and automated upgrades
  • Implemented linting, testing and error tracking standards (ESLint, Stylelint, Sentry) across all projects
  • Conducted technical interviews, performance evaluations and supported recruiting
Sep 2013 - Aug 2016
3 years
Munich, Germany

Frontend Developer

SnipClip die digitale Fabrik GmbH

  • Developed interactive web applications, campaigns and communities integrating Facebook, SoundCloud and Instagram APIs
  • Built a mobile web app with an offline-first approach and local caching for improved availability
  • Designed and prototyped a native iPhone and Apple Watch app with Swift
  • Developed a working prototype for a video chat application with WebRTC
  • Introduced modern frontend toolchains (Gulp, Babel, Sass, Autoprefixer) to increase development speed
  • Migrated new projects from server-side rendering with jQuery to modern single-page applications with AngularJS
  • Supported backend with PHP, Symfony and MariaDB and deployed on AWS/CloudControl
  • Promoted to partner of the company due to outstanding performance

Summary

Experienced Senior Fullstack Developer with over 10 years of professional experience in building modern web applications and accessible component libraries. Specialized in TypeScript, React, Vue.js and Node.js as well as accessible frontend architecture according to WCAG, BITV and EN 301 549. Experience in technical leadership, team mentoring and setting up sustainable DevOps and testing processes (CI/CD, GitHub Actions, Playwright). Combines deep technical know-how with a focus on developer experience, code quality and performance.

Skills

Frontend Development

  • Typescript, Javascript, Html5, Css3, Scss
  • Vue.js, Nuxt, React, Redux, Stencil, Angularjs, Next.js, Formik
  • Responsive Design, Design Tokens, Theming, Accessibility (Wcag 2.1, Bitv, En 301 549, Nvda, Voiceover)
  • Progressive Web Apps, Offline First
  • Eslint, Stylelint, Sentry, Storybook, Lighthouse, Core Web Vitals

Backend Development

  • Node.js, Express, Java, Spring Boot
  • Rest Apis, Microservices, Mysql, Mariadb, Oracle

Testing & Qa

  • Jest, Vitest, Playwright, Backstop.js, Axe
  • E2e Testing, Visual Regression Testing, Tdd

Build & Devops

  • Npm, Pnpm, Webpack, Vite
  • Docker, Jenkins, Github Actions, Gitlab Ci
  • Monorepos, Ci/cd, Dependency Management

Methods & Collaboration

  • Agile Software Development (Scrum, Kanban)
  • Version Control With Git (Github, Gitlab, Bitbucket)
  • Project And Knowledge Management: Jira, Confluence
  • Code Reviews

Languages

German
Native
English
Advanced

Education

Aug 2010 - May 2013

Webmasterware.net GmbH

IT Specialist in Application Development · Trier, Germany

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