Freelance · available for projects & training

Modern web frontends
built to last.

I am a freelance developer, consultant and trainer for modern web frontends, with a clear focus on AI in the frontend and accessibility. Since 2013 I have been guiding teams from architecture all the way into production.

Discuss a project AI in the frontend
Stack
AngularTypeScriptReactRxJSWeb ComponentsAccessibilityAI / LLMMQTT
Portrait of Karsten Sitterberg
Frontend & AIAngular · React · TS
MSc PhysicsAnalytical by training
Freelance since 2013Frontend · Web · AI
Conference speakerJAX · iJS · IT-Security
JUG Münster& Frontend Freunde

// Services

How I can help

Three closely related areas, on their own or combined, always grounded in real project experience.

Development

From architecture to production: modern web frontends built with Angular, React and TypeScript, accessible by default and cleanly wired up to your APIs.

Consulting

An independent second opinion, code reviews and architecture advice. I pinpoint the actual problems, defuse the risks and map out options that will hold up.

Training

Hands-on training, workshops and coaching, remote or on site. Tailored to your team and focused on what really matters in your project.

All services & focus areas

// Focus area

AI in the frontend, from idea to feature

Large language models are changing how applications are used. I help teams bring AI into the frontend in a sensible and secure way: assistant and chat interfaces, generative features, RAG integration, cleanly embedded in Angular, React and your existing backend.

More on AI in the frontend
Typical building blocks
  • Assistant & chat UIs with streaming and tool calling
  • Generative features right inside the user flow
  • RAG & knowledge access across your own data
  • Security & data protection considered from the start
Karsten Sitterberg speaking on a conference stage
SpeakerRegularly on stageTalks and workshops at JAX, W-JAX and other conferences.

// Explore

Dig deeper

Training

Angular, React, TypeScript, accessibility, MQTT and AI in the frontend, hands-on and tailored to your team.

See the training topics

Talks & publications

Active as a speaker and author at JAX, entwickler.de and heise Academy.

See where I show up

Profile

Physicist, frontend specialist and community organiser from Münster, freelancing since 2013.

About me

// Contact

Let’s talk.

A project, a training request, an AI initiative in the frontend or an independent second opinion? Drop me a line and I’ll get back to you shortly.

Send an enquiry Contact & details