Principal Engineer Lausanne, Switzerland
Mirek Rusin.
Simple components.
Complex systems.
Languages, developer tools, and open source.
Exploring the technology around LLMs.
Independent work
Ideas, made into tools.
Open source & public domain
Featured project
cave
Compressed Atomic Verb Expressions
A small, line-oriented language for persisting knowledge as composable, atomic claims — subject VERB object. Easy for humans and LLMs to write, easy to diff, stored in SQLite, formal enough to query as an information graph.
caveatomic claimsSmall claims.
Composable · Queryable · SQLite
Connected knowledge.
prelude
Standard library-like packages for TypeScript
A monorepo of small, focused @prelude/* packages — data structures, concurrency primitives and utilities — each independently published, typechecked and property-tested.
mq
jq for Markdown
Query Markdown documents by their structure from shell pipelines or JavaScript, using CSS-like selectors over the Markdown tree, while preserving the original source.
mssqlite
SQLite-backed, Microsoft SQL Server compatible server
A TDS 7.4 server speaking SQL Server’s wire protocol and T-SQL, storing everything in SQLite via node:sqlite. Real MSSQL clients connect unmodified — no native dependencies.
ast
Unified graph of ASTs
One typed node-graph model, lazy query algebra and change-planning runtime for heterogeneous structured resources — repositories, source code, documents and databases.
throwscript
Every throw gets a @throws
A linter-like checker built on the TypeScript compiler API that asserts every function that can throw (or reject) carries a JSDoc @throws tag with the right error type — and can insert the missing ones.
linuxOS
Make Ubuntu feel like macOS
Ubuntu/GNOME configuration for running Linux alongside Apple peripherals — Studio Display brightness with the native OSD, Magic Keyboard remapping, Cmd-C / Cmd-V in the terminal.
A little background
Beyond the code.
Principal Engineer at Applied Blockchain / Applied Edge, currently working with Shell Trading & Supply. Based in Lausanne, Switzerland since 2018.
Building open source and public domain software on the side in TypeScript, C, C++, Rust, Go, OCaml, MoonBit, and others.
Interested in open-weight models, llama.cpp, and the tools around LLMs: MCP servers, ACP, harness development, integration, and automation.
The archive
Earlier explorations.
Objective-C, C & Node.js · The 2010s
YAML.framework
YAML for Objective-C, based on libyaml
CoreWebSocket
WebSocket server and client for iOS and macOS in Core Foundation style
node-rus-diff
JSON diff
node-unused-deps
Report unused npm packages
CoreJSON
Core Foundation JSON built on libyajl
CoreSQLite3
SQLite3 for iOS and macOS
rb_tree
Red-black tree in C
node-json-criteria
Mongo-style criteria queries on JSON objects
Quartz Composer plugins
WebSocket, OpenCV, VNC, Objective-C and movie export plug-ins