Applied curiosity / open tools / field notes
Vienna / 48.2082 N / 16.3738 E / 20 C / cloudy
Thinking with machines.
This is the personal site of Lukas Stepanek: technical work, careful writing, and human-scale questions about thinking with machines.
Research, writing, and experiments from the edge where ideas have to meet tools, limits, and other people.
papers / constraints / technical notes
tools / projects / useful lessons
notes / fragments / field observations
email / github / say hello
currently resident
arXiv preprint
route-block arithmetic
evidence artifacts
field observations
Current signal
Alignment can be arithmetic control flow.
MoE inference groups routed rows into padded expert blocks before packed matrix multiplication. In one pinned Qwen3-Coder AWQ fixture, moving two selected routes across a block boundary transferred the exact arithmetic trajectory; changing their order inside one block did not.
The result is causal for one controlled fixture, not a prevalence, portability, performance, or serving-impact claim. The paper and its recorded-evidence artifact are public.
Read the paper noteResearch
Where ideas meet limits.
Papers, technical notes, and implementation questions around practical ML systems.
arXiv preprint
Resident KV Claims
A semantic contract for how inference runtimes should behave when resident KV blocks and active KV pressure compete for the same memory pool.
arXiv preprint
Fail-Closed Lowering Of Resident KV Claims
A Resident KV paper on when runtime primitives, adapters, or patches can be treated as evidence for accepted future-KV obligations.
Signals
Notes, fragments, and field observations.
Field note / May 28, 2026
The Win Was To Move The Cost
A local vLLM/Mooncake field note: user-path restore lost, request-shaped background prewarm amortized, and the controls separated native prefix/cache-key reuse from semantic adoption.
Field note / May 23, 2026
The Dream Is Large. The Claim Is Small.
A first field note on the Resident KV Claims paper, open-source ambition, and why a bounded runtime contract can still feel like a real contribution.
Field note / May 24, 2026
A Used 3090 And The Shape Of The Work
A personal field note on open-source ambition, accidental hardware constraints, information overload, and why local AI work had to become more evidence-bound.
About
Technical work, kept in proportion.
This site belongs to Lukas Stepanek, also known as krooksn / krx in some corners of the internet. I am an independent researcher and builder based in Vienna, with most of my attention on machine learning systems, autonomous agents, practical research tools, and the constraints that show up on real machines.
I care about open-source communities, serious technical practice, and a life that still has texture outside it.
Read the longer storyContact
Drop me a line.
Research questions, open-source projects, writing, or a conversation are all welcome.