Lebenslauf von Tobias Engelberg

About me

I am a Senior Frontend Developer with a focus on UI/UX-driven web applications, modular frontend architectures, and scalable design systems. I develop user-centered features from concept (user flows, interaction design) through implementation in accessible, maintainable components. I place strong emphasis on clear component structures, consistent user experiences, and close collaboration with design, product, and backend teams. A solid understanding of API and data flow integration enables me to think about systems in a holistic way.

Education

High School Diploma (Abitur)

Viktoria-Gymnasium • Essen, Germany2002 – 2011

Completed an advanced project in computer science and participated in the “Jugend forscht” competition (2nd place in Computer Science/Mathematics) with the topic “Authentication via smart card on the web.”

B.Sc. Applied Computer Science (Media Informatics)

University of Duisburg–Essen • Duisburg, Germany2012 – 2017

Professional Experience

Frontend Developer (Freelance Project)

Project at LUMASERV GmbH • Koblenz, Germany2026 – Present

Further development of a complex React/TypeScript frontend with extensive form logic and dynamic validation rules.
REST API integration using TypeScript,Zod schema validation, and structured data mapping.
Development of a reusable UI component library using TailwindCSS.
Testing strategy including unit tests (Vitest) and end-to-end tests (Playwright).

Fullstack Developer, UI/UX Designer

Fronius International GmbH | Fronius Solar Energy • Vienna, Austria2021 – Present

Solar.web (Greenfield, B2C & B2B)
Web portal for B2C PV monitoring for system owners · B2B fleet management & system monitoring for operators with plant fleets.

End-to-end responsibility within a 10-person agile Scrum team in the greenfield redevelopment of Solar.web for B2C & B2B customers.
UI/UX concept together with Product Owner and Product Management (user flows, prototypes, Figma).
Frontend development with Angular & TypeScript, using TanStack Query and NgRx for state management.
Support in backend development with C#/.NET as well as an API-first approach.
Quality assurance: E2E tests (Playwright, Cucumber), unit tests (Jasmine) and CI/CD for continuous delivery.
Focus on accessibility (WCAG 2.1 AA) and scalable frontend architecture.

Fronius Design System
Company-wide design system for consistent, reusable UI components.

Concept & implementation as an Angular & Web Components library (incl. HTML components) for consistent, reusable UI across all product teams.
Development of a scalable UI library with clear API contracts, tokens, and themeable components.
Documentation in Storybook (examples, usage guides, accessibility notes) and DX improvements (playground, snippets).
Processes & guidelines: changelogs, review/approval flow, visual regression testing – ensuring consistency and maintainability.

Fullstack Developer

RTL Technology GmbH, formerly CBC GmbH • Cologne, Germany2019 – 2021

Further development of kochbar.de: introduction of a modern frontend architecture with Vue.js, React & TypeScript, component-based UI development.
Building a push architecture (Laravel, RabbitMQ, Redis) for high-performance content distribution.
Collaboration with UX design to validate features through A/B tests.
Strong focus on SEO & performance optimization (Core Web Vitals, Lighthouse).
Step-by-step modernization of legacy code and introduction of new standards.

Fullstack Developer, UI/UX Designer

green|connector GmbH / con|energy ag • Essen, Germany2017–2019

Greenfield development of multiple web applications for the energy and e-mobility market:
- B2B marketplace for energy efficiency products
- B2C portal for e-mobility
Frontend development with Angular, TypeScript, SCSS, Angular Material, state management with NgRx. Backend development with Node.js, MySQL, PostgreSQL, MongoDB & Elasticsearch.
Operations on AWS (EC2, Elastic Beanstalk, S3, CloudFront, Lambda, Amplify, API Gateway).
Design of responsive, modular white-label designs (UI/UX) and integration and analysis of analytics & tracking.

Reference letter: green|connector GmbH
PDF document

Freelancing as Web Developer, UI/UX Designer

Self-employed • Austria, Germany2013 – Present

Selected Projects:

Web platform for a publicly funded organization

Development of an accessible website using Next.js & TypeScript
Integration of a headless CMS (Strapi).
Design of modular component structures for multiple independent network sites.

Interactive exhibition app “OKtoRail” (Essen)

Development of a mobile cross-platform app based on Cordova
Integration of beacon technology for location-based content delivery
Concept and implementation of the user interface

Various web projects (SMEs & organizations)

Implementation of responsive websites with a focus on performance, usability & maintainability
Technical consulting on architecture and framework decisions
Close coordination with design and clients

Working Student: Fullstack Developer

neomatt GmbH • Essen, Germany2013 – 2017

Development and operation of complex web applications and mobile Cordova apps.
Technologies: jQuery, jQuery Mobile, Ember.js, Grails, REST APIs
Installation, configuration, and maintenance of Linux-based server services (nginx, Froxlor, mail server, Jenkins).
Maintenance and ongoing operations of Magento-based shop systems.
Customer support and technology consulting (framework selection, architecture).

Reference letter: neomatt GmbH
PDF document