available for fractional CTO work
Founder of StackForge ↗
Fractional and interim CTO for DACH teams
I build EU-sovereign, GDPR-native software.
About supporting this work. I publish open source software. If it is useful to you, you can support it through Buy Me a Coffee. Any support is a voluntary donation, not a purchase. You receive no goods, products, or services in return.
I am a software engineer and technical founder based in Weihmichl, Lower Bavaria. I build and ship full-stack TypeScript software that has to hold up under real operational constraints and German regulatory requirements, and I work as a fractional and interim CTO for teams in the DACH market. My full work history is on my CV.
Through StackForge I build independent products and open source, and I take on selected client work as a fractional and interim CTO. The thread through everything I build is EU digital sovereignty and GDPR compliance as a default rather than an afterthought: data stays in the EU, tooling is self-hostable, and privacy is a design constraint from the start.
Outside of building products I serve as an IHK examiner and help organise JSCraftCamp Munich, a community unconference.
Full-stack TypeScript, end to end, with the infrastructure and regulatory context to ship it in regulated EU markets.
Open source work and products. The libraries are public so you can read the code before you trust it.
Open source TypeScript library for Factur-X, ZUGFeRD, and XRechnung electronic invoicing. It generates and reads the hybrid PDF and XML formats required for compliant e-invoicing in Germany and the EU. Licensed under EUPL-1.2.
TypeScript · EUPL-1.2 · e-invoicing
EU-hosted link-in-bio, short link, and digital business card platform. A GDPR-native alternative to Linktree and Bitly, with data kept in the EU.
product · EU-hosted
EU-hosted, GDPR-native operating system for small German-speaking creators who are starting to earn from their reach. Bundles link-in-bio, an AI-sorted managed inbox, deal management, GoBD-compliant invoicing, secured payments, and Impressum protection in one platform.
creator platform · EU-hosted
Where my independent products and open source work live, focused on EU digital sovereignty and GDPR-compliant SaaS.
products · open source
Visitor management software for the DACH market, positioned around NIS-2 and ISO 27001 requirements for organisations that need auditable access and visitor records.
product · DACH · NIS-2 / ISO 27001
Browser-based savegame editor for the Gothic 1 Remake.
web tool · open source
Lockpicking solver for the Gothic 1 Remake.
web tool · open source
Available as a fractional or interim CTO for DACH companies that need senior technical leadership without a full-time hire.
Part-time technical leadership for founders and teams: architecture, hiring, roadmap, and the decisions that are expensive to get wrong.
Designing systems that keep data in the EU and stay self-hostable, so you are not locked into a single cloud or a single jurisdiction.
Building privacy and German regulatory requirements (GDPR, GoBD, NIS-2, ISO 27001) into the product rather than bolting them on later.
Hands-on delivery from PostgreSQL up to web and mobile, with AI engineering and spec-driven development as part of how the work gets built.
For consulting enquiries, email tobias.sittenauer@stack-forge.eu.
The fastest way to reach me is email. I read everything.