and-rs.dk

Systems Programming & Consulting

Copenhagen · Available for short and long engagements

I can make computers do anything

About

I’m a distinguished systems programmer specialising in low-level software and with interests in operating systems, reverse engineering, and cryptography.

I build robust software for devices and don't give up.

Can quickly understand large codebases. Still remember how to build old fashioned simple systems from the ground up without bloated frameworks and AI slop.

Will do what gets the job done no matter if that means fixing the deploy pipeline, mentoring new engineers, researching or just building the scripts that no one thought of that makes everybodys lives easier.

Mission Patch

I Have broad knowledge and the ability to go in-depth when needed. And have experience across diverse industries like telecom, automotive, aeronautics, medical devices, HPC and Industrial control systems

What I do

I've gotten my hands dirty working on

Operationg Systems: Drivers, boot & init, containerization, fast boot times, minimal image sizes
Embedded & hardware: Bringup, debugging, board support, toolchains, diagnostics, factory tests
Software reverse engineering: Malware analysis, app reverse engineering, legacy systems, cracks, keygens, pentest
Protocol/format analysis: Interoperability, dissectors (for wireshark/kaitai/hachoir...), binary formats, data-recovery
Crypto & security: Integration, digital signatures, ciphers, key handling, authentication, PKI
Tooling, automation & devops: Build-systems, boot-strapping, reproducible builds, CI, format converters, data pipelines, SDKs
Porting & modernization: Platform moves, ABI/API shims, refactors, test harnesses
Analyze refactor and simplify large codebases without loss of generality
Document autogeneration: documents from code, diagram generation, document generation
Production software: services, interfaces, protocols

Also happy to jump into cloud/web, GUI apps, relational databases, GIS processing/rendering, format conversion, and all the scripted glue that makes real systems work.

Or dive into new areas

Industries & domains

Telecommunication · Automotive · Aeronautics · Medical devices · Industrial control systems Defense · Relational DBs · HPC

How I work

Engagements: fixed-scope, time & materials, or retainer.
Collaboration: comfortable in solo roles or embedded in teams.
Delivery: clear scope, small increments, documented artifacts, knowledge transfer.
Hollistic approach: I keep the entire system in mind, even when diving into specifics.
Responsibility: Since my first job, I have been responsible for at least one product everywhere I worked.

I like

Good old-fashioned software that works
Immutable systems with small state
Reproducible compact firmware images
- e.g.: linux+rootfs+python <= 7MB
- fast boot times
- no bloat - I hate bloat
Defensive programming
Completing projects
Creative freedom
Taking things apart
- putting them together in new ways
CTFs · crypto challenges · puzzles
Zines: PoCoGTFo · phrack · Paged out!