Hi, I'm rti
Software Product Engineer
FullStack
DevOps
ML
20+ years experience building and maintaining tech products in production
Home in a GNU/Linux shell, in love with the open source ecosystem
Performing best in culturally diverse cross functional product teams
Building products with a continuous focus on user experience
Selected projects
A shortened list of my work. Want to see more? Contact me!
2023 - today
Production System
Wikibase Suite
Wikimedia Deutschland e.V.

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.

TypeScriptJSPHPJavaMariaDBElasicSearchBlazegraphDocker/Compose/Hubwebdriver.ioBashNXGithub/ActionsCI/CDSemVerConventional Commits
2005 - today
Production System
image generated
rtti.de Cloud Services
voluntary

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.

Bare metal hostingLinuxNixOS/AnywhereDiskoApacheNginxMariaDBPostgreSQLPostfixDovecotRSpamdACME/Let's EncryptNextcloudWordPressGit hostingBorg Backup
2023 - 2024
Research Project
image generated
Askwikidata
Wikimedia Deutschland e.V.

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, leveraging multicore processing and distributed computing methodologies.

PythonpytorchLLMsEmbeddingsRerankerstransformersRAGMultiprocessingDask ClusterLinuxROCm/CUDANixTerraform/OpenTofuNixOS AnywhereOllamaPostgreSQL/pgvecto.rsKnowledge Graphs
2021 - 2022
Production System
dot.base Digital Health Records
Charité Universitätsmedizin Berlin

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.

TypeScriptVue.jsTailwindNodejsexpressFHIRJavaSpringPostgreSQLGithub/ActionsCI/CDDocker/Compose/SwarmTraefikACME/Let's EncryptBashGraphana/PrometheusSnykSemVerConventional Commits
2011 - 2017
Production System
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Solar Home System Firmware Lead
Mobisol Group

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.

Embedded-CAVR ATmegaAVR-GCCavrlibcmakeADCGPIOSPIFlashUSARTGSMSMSGPRSHTTPRESTRSAGitLabCIJenkinsPythonpytest
2010 - 2011
Production System
Ryzom Core MacOS X Port
voluntary

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.

Mac OS XCocoaC++Objective-CGCCGDBXCodeCMakeOpenGLOpenALRedmineMercurial