Stefan Dietz - Frontend Developer – Sports Event and City Portal Projects

Q: Where is Stefan based?

Stefan is based in Neubiberg, Germany .

Q: What languages does Stefan speak?

Stefan speaks the following languages: German (Native), English (Advanced) .

Q: How many years of experience does Stefan have?

Stefan has at least 12 years of experience. During this time, Stefan has worked in at least 4 different roles and for 4 different companies . The average length of individual experience is 3 years and 1 month . Note that Stefan may not have shared all experience and actually has more experience.

Q: What is Stefan's latest experience?

Stefan's most recent position is Frontend Developer – Sports Event and City Portal Projects at München Betriebs GmbH .

Q: What companies has Stefan worked for in recent years?

In recent years, Stefan has worked for München Betriebs GmbH , ITZBund , and CHECK24 Vergleichsportal Baufinanzierung GmbH .

Q: Which industries is Stefan most experienced in?

Stefan is most experienced in industries like Banking and Finance , Information Technology (IT) , and Government and Public Administration . Stefan also has some experience in Sport and Recreation .

Q: Which business areas is Stefan most experienced in?

Stefan is most experienced in business areas like Information Technology (IT) , Quality Assurance (QA) , and Project Management . Stefan also has some experience in Product Development .

Q: Which industries has Stefan worked in recently?

Stefan has recently worked in industries like Banking and Finance , Government and Public Administration , and Sport and Recreation .

Q: Which business areas has Stefan worked in recently?

Stefan has recently worked in business areas like Information Technology (IT) , Quality Assurance (QA) , and Project Management .

Recommended expert

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 8 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

Industries Experience

See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.

Experienced in Banking and Finance (7 years), Information Technology (3 years), Government and Administration (2.5 years), and Sport (1.5 years).

Banking and Finance

Information Technology

Government and Administration

Sport

Business Areas Experience

The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.

Experienced in Information Technology (12.5 years), Quality Assurance (8 years), Project Management (7 years), and Product Development (4 years).

Information Technology

Quality Assurance

Project Management

Product Development

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

Profile

Created

August 2025

Last Update

August 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Stefan based?

Stefan is based in Neubiberg, Germany.

What languages does Stefan speak?

Stefan speaks the following languages: German (Native), English (Advanced).

How many years of experience does Stefan have?

Stefan has at least 12 years of experience. During this time, Stefan has worked in at least 4 different roles and for 4 different companies. The average length of individual experience is 3 years and 1 month. Note that Stefan may not have shared all experience and actually has more experience.

What roles would Stefan be best suited for?

Based on recent experience, Stefan would be well-suited for roles such as: Frontend Developer – Sports Event and City Portal Projects, Lead Developer for the Accessible Component Library “KoliBri”, Deputy Frontend Team Lead.

What is Stefan's latest experience?

Stefan's most recent position is Frontend Developer – Sports Event and City Portal Projects at München Betriebs GmbH.

What companies has Stefan worked for in recent years?

In recent years, Stefan has worked for München Betriebs GmbH, ITZBund, and CHECK24 Vergleichsportal Baufinanzierung GmbH.

Which industries is Stefan most experienced in?

Stefan is most experienced in industries like Banking and Finance, Information Technology (IT), and Government and Public Administration. Stefan also has some experience in Sport and Recreation.

Which business areas is Stefan most experienced in?

Stefan is most experienced in business areas like Information Technology (IT), Quality Assurance (QA), and Project Management. Stefan also has some experience in Product Development.

Which industries has Stefan worked in recently?

Stefan has recently worked in industries like Banking and Finance, Government and Public Administration, and Sport and Recreation.

Which business areas has Stefan worked in recently?

Stefan has recently worked in business areas like Information Technology (IT), Quality Assurance (QA), and Project Management.

What is Stefan's education?

Stefan holds a Master in IT Specialist in Application Development from Webmasterware.net GmbH.

What is the availability of Stefan?

Stefan is immediately available full-time for suitable projects.

What is the rate of Stefan?

Stefan's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.