Karsten Lenz

Hi, I'm Karsten Lenz

UX Designer & Web Developer

I build digital products with measurable impact, from idea to implementation.

Let's talk!

About Me

I've been working in digital product development for over 16 years. Since 2026 I'm self-employed and happy to help you build digital solutions that solve real problems and create measurable value. I combine human-centered design with AI-assisted web development.

Thanks to the AI boost with Claude Code, I can deliver what used to require an entire team just a few years ago. That said, I don't do "vibe coding": I orchestrate the AI step by step, review every line, and complement the results with my own code. This way I leverage the speed gains on straightforward tasks while still ensuring high quality.

Skills: How I Can Help You

Design

  • UX Design (CPUX-F certified)
  • UX Management (CPUX-M certified)
  • Wireframing & Prototyping
  • UX Research and Usability Tests
  • Figma
  • Design Thinking
  • Workshop Facilitation (Design Thinking, Design Studio, Digital Strategy)

Development

  • HTML & CSS
  • JavaScript & TypeScript
  • React
  • Vue
  • Angular
  • Accessibility (WCAG 2.2)
  • Git
  • Test automation with Cypress, Vitest, Jest
  • AI-Assisted Coding: Claude Code, Cursor

Featured Projects

Project 1

360° Customer Service Cockpit

For a major German public transport company, I designed the customer service cockpit and also developed the frontend as part of the development team. Through user interviews and multiple usability tests, we created a tailored application that makes complex customer and order data quickly accessible. With measurable success: subscription creation now takes 5 minutes instead of 2 weeks.

UX Design User Research Frontend Development Vue
Project 2

Innovation Facilitation

From 2022 to 2024, I supported SachsenEnergie as a Design Thinking facilitator and UX designer as part of their "Ideenschmiede" (idea forge) program. Across various innovation sprints, I facilitated workshops to explore problem spaces and develop concrete solution ideas. Afterwards, I created storyboards and interactive prototypes that were user-tested and pitched to the management board.

Design Thinking Workshop Facilitation Prototyping

Happy to share more details in person!

Get In Touch

I'd love to hear from you, whether you have a specific project in mind or just want to chat about UX!