Hi! I am Stefan
I am a computer scientist with a passion for distributed systems and operating systems.I enjoy working on the intersection of theory and practice. I like to design challenging systems and explore their feasibility by building prototypes.
When I am not working, I enjoy all things tech. I spend more time than I care to admit optimizing my smart home installation. I also enjoy thinking about transitioning our world to sustainable energy and transportation, which is why I closely follow Tesla.
Of course, given my love for technology, I also closely follow SpaceX and their efforts to make humanity a multi-planetary species in Boca Chica.
NVIDIA
I am currently working at NVIDIA as a Senior Software Architect in the software networking organization.
I have been involved in researching options for timely telemetry data in large AI datacenter networks. We are also building a large scale GPU based network simulator to explore ideas for accelerating future datacenter networks.
I have been involved in researching options for timely telemetry data in large AI datacenter networks. We are also building a large scale GPU based network simulator to explore ideas for accelerating future datacenter networks.
Selected work:
- Research on timely telemetry data for AI datacenter networks
- NSX: Large-scale GPU-based network simulator for AI clusters, capable of simulating networks with 524k nodes
- Daily collaboration with NVIDIA's networking team on AI cluster design
DFINITY Foundation
Before NVIDIA, I was working as a Senior Researcher at the DFINITY Foundation in Zurich to help
build the Internet Computer, a platform for generic compute on decentralized infrastructure with byzantine fault
tolerance.
I worked with a smart team of excellent researchers and engineers on what could well be a revolution in the way we think about the internet.
I worked with a smart team of excellent researchers and engineers on what could well be a revolution in the way we think about the internet.
Selected work:
- Research lead of the runtime team
- Protocol Upgrades: I was helping to design and leading development of Internet Computer protocol upgrades. Upgrades are difficult because the IC is a decentralized and byzantine fault-tolerant system.
- Responsible for e2e system performance and scalability.
Oracle Labs
Before DFINITY, I was at Oracle Labs in Zurich,
Switzerland, where I was working, among others, with
Hassan Chafi,
Sungpack Hong and
Tim Harris.
Selected work:
- Callisto RTS: A runtime system for parallel applications with efficient work distribution down to small batch sizes to avoid work-imbalance. I also helped to extend it with Smart Collections, a programming language independent abstraction for data structures, which is tuning memory allocation to machine characteristics.
- PGX.D is a distributed graph processing framework. My main responsibility was to add fault-tolerance and elasticity to it.
In 2014, I also had the honor to finish an internship with Tim Harris at Oracle Labs in beautiful Cambridge, UK.
ETH Zurich
I earned my PhD from
the Systems Group
at ETH Zurich under the supervision
of
Prof. Timothy Roscoe. In addition to work on
the Barrelfish operating
system, I was leading two projects during my PhD:
Selected work:
- Shoal: A runtime for multicore machines that automatically tunes memory allocation and applies NUMA replication based on memory access patterns given by programmers or extracted by high-level compilers. During my time at Oracle, I helped include similar ideas to a production system as part of the PGX runtime.
- Smelt: A framework to automatically build low-latency message-passing tree topologies for multicore machines based on simulation on the pairwise latency of all CPUs.
IBM Research and Development
I wrote my diploma thesis at IBM Research and Development in
Böblingen, where I investigated the Performance of the VSAM file
system in the
z/VSE mainframe operating system.
Awards:
- SHARE award, second runner up, for my master thesis
KIT: Karlsruhe Institue of Technology
Before my time in Zurich, I studied at the Karlsruhe Institute of
Technology (KIT), during which I have been working as
research assistant in humanoid robotics and sensor
networking.
Notable work:
- Bachelor thesis on building a tool for annotating objects in a 3D environment.
