The internal mechanisms of Transformer Large Language models (LLMs) can be challenging to follow due to the vast amount of numbers involved. We humans can hardly form a mental model. This project makes these inner workings more tangible by providing visualizations of a Transformer's internal state. Utilizing a minimal dataset and a deliberately simplified model, it is possible to follow the model's internal processes step-by-step.

Nixwrap is a command line utility to easily wrap processes in a sandbox preventing them from accessing your system. Nixwrap can hinder access to environment variables, files, devices and the network. Under the hood, Nixwrap is based on Bubblewrap which in turn uses Linux Namespaces.

Wikibase Suite provides the software stack powering Wikidata as a production ready self-hosting solution.

We, as a cross functional team, adapt, test, package and release the software originally built for internal purposes as a suite of tools matching the requirements of external organizations.

In order to be in control of the IT infrastructure supporting our daily lives, I run a suite of services such as e-mail, cloud storage, contact and calendar synchronization, version control and Wordpress web hosting for some dozens of users.

The system runs on bare metal with a distributed backup strategy. The full setup is described in code using NixOS and NixOS Anywhere and therefore completely reproducible. All data is encrypted at rest. This allows low running costs while keeping the valuable user data safe.

Askwikidata guides LLM output using the Wikidata knowledge graph.

Text generated in response to user queries is grounded in Wikidata knowledge as well as directly references it. This leads to reduced hallucinations, up to date information as well as improved verifiability.

This project explores the possibilities and challenges of implementing retrieval augmented generation (RAG) on Wikidata's terrabyte scale data set.

Parts of this prototype supported the development of the Wikidata Embedding Project.

As a startup incubated at Charité Berlin, dot.base provides a digital health record system for highly specialized medical procedures. One of the key features is the ability to develop interfaces and medical processes on the platform itself in close collaboration with end-users.

In this early stage, we as a cross functional team managed all aspects of our operations, including software development of backend and frontend, testing, devops, documentation, public relations, design, funding and recruiting.

Mobisol provided off grid solar home systems to households in East Africa.

I developed the firmware for the remote controlled devices. The main requirements were to run on inexpensive hardware as well as to have a very short time to market. The firmware featured backend communication to a REST API via GPRS, fallback via SMS, RSA signature verification, data logging and more on an 8bit μC with 16kB RAM. Firmware updates via HTTP allowed a fast roll-out of early prototype systems, even though some features were initially missing.

Later I recruited and led a team of 4 firmware engineers supporting the full product life cycle including mass production and obsolescence. We maintained the software, added support for new hardware generations and implemented a custom real time charge controller on a smaller co-processor. CI tested our firmware on test hardware simulating various load and error situations.

When I left the organization, more than 50,000 systems have been deployed in the field. Mobisol has been later acquired by ENGIE.

When Nevrax released the source code of their MMORPG Ryzom, enthusiasts from around the world started to port the game client from Windows to Linux. I joined them to port the game client to Mac OS X Cocoa.

My work was concerned with adapting the core libraries "NEL - Nevrax Library" to Mac OS X by using the Cocoa framework for receiving input events from keyboard, mouse and touch screens, creating windows and rendering the game scene using OpenGL as well as bundling the game client as MacOS app bundle.

Later the game client was released to the Mac App Store and featured on several Mac news sites.