# Marc Krenn

> Designer turned full-stack developer in Vienna, Austria.

## About

Marc's work covers the full spectrum of digital product development – apps and web products, enterprise and internal tools, workflow automation, and the occasional AI/ML/LLM voodoo when it actually helps. He can take projects from early requirements to deployment, and he can handle the messy middle, too.

He tends to enjoy the weird, tricky problems with tight constraints, unclear paths, and the kind of work that needs creativity, adaptability, and a bit of stubbornness. His usual approach is simple. Figure out what people *actually* need, ship prototypes and MVPs quickly, then iterate until it feels right. He has a "getting shit done" attitude and a reliable set of tools and patterns he reaches for. If the project calls for it, he's also happy to switch stacks and learn new ones.

After wrapping up a long-term agency role, Marc moved into independent work to focus on projects that are exciting, meaningful, or ideally both.

## Experience

- 2025–now: Independent Developer – Building his own products and taking on select client work.
- 2023–2025: AI/ML Department Lead at a digital agency – Built and led a small team. Mostly LLM tooling and automation, plus some classic ML.
- 2020–2023: iOS Developer – Loved the excellent tooling that underpins iOS development.
- 2011–2020: UI/UX Designer – Design, prototyping, and user testing for clients across the DACH region. Later, he stepped into a lead role and ran workshops and gave talks.
- 2010–2015: Industrial Design at University of Applied Arts Vienna (Hartmut Esslinger) – Product and interaction design. Dropped out.

## Projects

- Claude Code Changelog (https://x.com/ClaudeCodeLog): X bot tracking Claude Code CLI changes, feature flags, and prompt updates.
- Client Work: Work across physics, health and sport – ML, UI/UX design, and full-stack development.
- To Be Announced: New project using open government data for business intelligence.

## Contact

- Email: mail@marckrenn.dev
- X/Twitter: https://x.com/marc_krenn
- Bluesky: https://bsky.app/profile/marckrenn.bsky.social
- GitHub: https://github.com/marckrenn
- Substack: https://substack.com/@marckrenn
- Hacker News: https://news.ycombinator.com/user?id=marckrenn
- LinkedIn: https://www.linkedin.com/in/marc-krenn-01401b50/

## Content

Marc's blog (which he calls "Brainwaves") features technical articles and whatever else is on his mind.

- Blog: https://marckrenn.dev
- RSS Feed: https://marckrenn.dev/feed.xml

## Legal

Marc Krenn dev. e.U.
Leopold-Ferstl-Gasse 3/50
1210 Vienna, Austria
Commercial Register: FN 665171v (Handelsgericht Wien)
VAT ID: ATU82509616