Sebastian Werner

3Degrees · Meridian

November 2025–present · Senior Principal Frontend Architect · US-client engagement

I lead work on visual quality, internationalization, and frontend performance for an energy-management product. My work includes marketplace and public product pages, mobile layouts, SEO, and separate rendering paths for public pages and authenticated portals.

I introduced application localization and migrated the runtime from Lingui to Palamedes, including per-request language handling and translation-catalog boundaries between server and client code. Performance work covers language-specific HTML and data caching, reduced client-side work, and progressive streaming of portfolio information. The team works entirely in English and uses AI-supported development extensively.

Relevant technologies: TypeScript, React, Next.js, Palamedes, Lingui, Vercel, Cloudflare, Supabase.

Regrello

October 2024–September 2025 · Frontend Internationalization Lead · US-client engagement

I led the internationalization of an established enterprise application. I integrated localization into the UI and built catalog extraction, compilation, and LLM-assisted translation workflows. These workflows retained translation metadata and language-specific terminology.

As part of a shared initiative, I implemented review interfaces for translated user content. They covered rich text, mention placeholders, permission-sensitive editing, and asynchronous states.

I also migrated the frontend workspace from NX to Turborepo, introduced strict type-aware linting, and automated GraphQL enum-to-union migration. I separated component-development dependencies from the main application and added targeted UI and end-to-end tests.

Relevant technologies: TypeScript, React, GraphQL, Lingui, Vite, Turborepo, Storybook, Playwright.

EnBW · Customer Portals and Support Workbench

June 2022–February 2024 · Frontend Expert / React Architect

I contributed frontend architecture and implementation to customer self-service and support applications. The white-label platform supported tenant-specific features, content, communication options, and visual identity. Customer workflows included contracts, invoices, meter readings, tariff changes, and relocation.

I built the PNPM/Turborepo workspace, shared theme and configuration packages, Storybook foundations, typed API integration, and reusable data-access utilities. I documented how to separate routing and data integration from reusable, API-independent presentation layouts. The architecture used headless UI primitives and typed style/asset themes.

Relevant technologies: React, TypeScript, PNPM, Turborepo, Vite, Storybook, Radix, VanillaExtract, SWR, REST, GraphQL.

Azeti · Industrial Monitoring Platform

March–May 2022 · Senior React Developer

I helped develop an industrial monitoring product with a white-label frontend. My work covered the NX monorepo, internationalization, theming options, and application components.

Relevant technologies: React, NX, internationalization, theming.

Netze BW · Customer Portal

February 2021–February 2022 · Lead Web Frontend Architect

I worked on architecture and development of a customer portal for master data and photovoltaic-installation management. I combined API-first development with architectural improvements, feature design, and Cypress-based end-to-end tests. The team included external specialists, CGI consultants, and internal project and UX staff.

Relevant technologies: React, REST, Cypress, API-first development, Scrum.

empiriecom · Otto Group

November 2020–February 2021 · Frontend / GraphQL Development Support

I supported GraphQL and frontend development within the Otto Group. I worked on resolvers, database integration, typing and testability, and a shared component library. I also helped identify conceptual gaps and clarify implementation questions.

Relevant technologies: GraphQL, Apollo, TypeScript, Node.js, MySQL.

HeidelbergCement / Heidelberg Materials

June 2019–September 2020 · React Architect

I developed and modernized web applications, including a truck-tracking interface with a heuristic for route visualization. My work included a shared frontend monorepo, Azure/CDN deployment tooling, TypeScript migration, API-client improvements, and Cypress tests. I worked with UX designers on reusable React interface foundations.

Relevant technologies: React, TypeScript, Google Maps, Azure, CDN, Cypress, Axios.

GE Healthcare

February 2019 · React Training and Mentoring

I delivered a workshop on React architecture, project structure, assets, TypeScript, server-data interaction, Redux conventions, and GraphQL. The workshop focused on applying these concepts to frontend design and implementation.

Relevant technologies: React, TypeScript, Redux, GraphQL.

Witt · Otto Group

September 2018–June 2019 · React / GraphQL Architect

I worked on a multilingual, multi-brand commerce platform with product pages, a basket, and customer accounts, including internationalization for Eastern European markets. On my initiative, we introduced GraphQL to orchestrate multiple backend services and give the frontend a consistent API.

I worked on server-rendered shop pages, incremental client loading through code splitting, efficient bundles, and Webpack/build tooling. The development workflow included performance monitoring. I also worked on routing and preloading, SSR-compatible user handling, and developer mentoring.

Relevant technologies: React, Apollo/GraphQL, SSR, Webpack, Babel, code splitting.

SWR · ARD Mediathek

July–September 2018 · React / GraphQL Development

I contributed to the shared ARD media-library frontend for HbbTV televisions and desktop, tablet, and mobile browsers. I integrated GraphQL over existing REST APIs and implemented frontend features under constrained-device performance requirements.

Relevant technologies: React, GraphQL, REST, HbbTV, responsive interfaces.

INIT · Public-Transport Information Dashboard

April–July 2018 · React Architect

I worked with product and development leadership on the architecture and implementation of a real-time transport-information dashboard. My contribution included API orchestration, geographic data presentation, reusable interface components, and React knowledge transfer.

Relevant technologies: React, Apollo/GraphQL, REST, Mapbox, OpenStreetMap.

Traton · RIO

January–March 2018 · Senior React Developer

I helped develop an existing telematics platform for logistics companies in a distributed team. I contributed application code, architecture suggestions, and mentoring.

Relevant technologies: React, Redux, Webpack.

coliquio

June–December 2017 · React / Frontend Architect

I worked on a new application connecting pharmaceutical representatives and physicians. I restructured a component library and contributed responsive layouts, typography, server rendering, and code splitting. I also evaluated interface components, advised on architecture, and trained developers.

Relevant technologies: React, SSR, CSS Grid, Webpack, component libraries.

Deutsche Bank · BluePort Corporate Banking

2017 · Frontend Architect

I contributed frontend architecture and technology decisions for a corporate-banking platform. I worked on technical guidance, reviewed code for two offshore development teams, and helped plan their development environment.

Relevant technologies and methods: React, Git-based review workflows, SAFe/Scaled Agile, distributed-team enablement.

Berlitz · Language-Course Portal

2016–2017 · React / Frontend Architect

I worked on a portal for planning and delivering language courses. I simplified frontend architecture and tooling, contributed GraphQL/Apollo integration, and supported implementation and the development team.

Relevant technologies: React, Apollo/GraphQL, Webpack.

DIY Retailer · Online Shop

2016 · React Development and Architecture Support

I developed the shop frontend and its tooling, including PostCSS, React hot-module replacement alongside server rendering, and internationalization. I also worked on separate application output for desktop and mobile interfaces.

Relevant technologies: React, React Intl, SSR/HMR, PostCSS, Webpack.

Cleverbridge · Customer Portal

April–May 2016 · React Development

I supported AOE in evaluating Vue and React, then contributed to the React implementation of Cleverbridge's customer portal.

Relevant technologies: React, Vue evaluation.

Deutsche Asset & Wealth Management / Deutsche Bank · Robo-Advisor

2015–2016 · Lead Frontend Architecture and Development

I worked with a small specialist team on an investment application. I built frontend foundations and interactive charts showing portfolio value and potential development, selecting Vue for the interface and D3 for visualization. The project followed formal requirements, approval procedures, and release processes.

Relevant technologies: Vue, D3, Sass, JavaScript.

Huawei / Deutsche Telekom · EntertainTV

June 2014–October 2015 · Frontend / UI Architect

I worked on the interface for a new generation of Telekom set-top boxes. The hardware required careful performance work to deliver demanding visual design, animation, and interaction.

I implemented animations, layouts, and the electronic program guide, tuned UI performance, and coordinated with on-site and offshore developers and design stakeholders.

Relevant technologies: JavaScript, Velocity.js, UI animation, constrained-device performance, frontend tooling.

MAGIX and TeleColumbus · Triplesense Reply

2013–2014 · Frontend Development

I worked on a responsive MAGIX website and a mobile TeleColumbus product/order application. For MAGIX, I developed viewport-based typography, interface behavior, and product-finder/comparison features. For TeleColumbus, I worked on client-side navigation, templated interfaces, form feedback, and PHP/RPC integration.

Relevant technologies: JavaScript, HTML/CSS, Sass, Jasy, RPC.

Deutsche Telekom · Telefoniecenter

November 2012–April 2013 · Frontend Development and Architecture

I built frontend functionality for fixed-line telephony configuration, including call forwarding, blocked callers, and tariff options. The implementation used MVP-style templates, REST integration, live validation, and background synchronization, with Core and Jasy infrastructure.

Relevant technologies: JavaScript, HTML5, REST, Core, Jasy.

Zynga

April 2011–November 2012 · Senior JavaScript Developer

I worked on HTML5 game infrastructure, UI performance, and developer tooling in a large JavaScript environment. Core and Jasy were developed on our own initiative and used extensively at Zynga: Core as the base library for our games and Jasy for their build process.

Both were developed further during the engagement, including framework, compiler/build, translation, asset, and development-server capabilities. My scrolling and animation work addressed the runtime demands of large game interfaces.

Relevant technologies: JavaScript, HTML5, Python, Core, Jasy, performance tooling.

Deutsche Telekom · Unify and Early Tolino Software

2009–2011 · Frontend Architecture and Development

I contributed to Unify, Deutsche Telekom's open-source framework, and worked on a soccer app built with PhoneGap and Unify. I also developed early Tolino software for desktop browsers, using qooxdoo, rich animations, and efficient ePub rendering.

Relevant technologies: JavaScript, qooxdoo, Unify, PhoneGap, ePub, UI animation.

studiVZ

October 2008–February 2009 · JavaScript Team Lead

I led a team of four frontend specialists working on a rapidly grown codebase. I developed interface components, including a photo viewer with person tagging.

Relevant technologies: JavaScript, interface architecture, team leadership.

1&1 · qooxdoo

November 2004–September 2008 · Lead Developer

I led development of the qooxdoo JavaScript UI framework. My work covered component and property systems, widgets, layout and rendering infrastructure, internationalization, and keyboard and focus behavior. I also worked on Python-based JavaScript compilation/build tooling, the open-source community, and technical presentations.

Relevant technologies: JavaScript, Python, UI frameworks, compiler/build systems, internationalization.

Schlund+Partner / 1&1

May 2002–October 2004 · Web Developer

In my first employed development role, I worked on recursive XSLT/Pustefix templates for products and ordering. I also developed client-side JavaScript/CSS interactions and worked on the DSL storefront, Control Center, and newsletters.

Relevant technologies: XSLT, Pustefix, JavaScript, CSS.