Matthias Görgens

Submissions for the puzzle closed on 4 September 2026.

Bcachefs is a copy-on-write filesystem for Linux.

There is a Code Golf Stack Exchange challenge from 2020 called Fastest yes in the west.

The Bitcoin Piñata was a MirageOS unikernel holding the private key to 10 BTC.

Anthropic made auto mode the default in Claude Code, and the Hacker News thread about it is full of a complaint I recognise: These models generate the most unreadable bash commands I’ve ever seen.

A LinkedIn “recruiter” pitching an AI-DeFi job sent me a project archive (DeFi_share.zip).

I have a bit of an obsession with undefined behaviour in C, and this year, some time on my hands due to paternity leave.

This one was, essentially, a one-shot AI solution, so let me lead with that.

The ITA Software hiring puzzles, preserved on the Internet Archive — Sling Blade Runner is among them.

Everyone who runs a service has the dashboard: p50, p95, p99 latency.

Comparison-based priority queues cost logarithmic time per operation, and that is not an engineering shortfall, it is a theorem.

A recurring theme on this blog is handing your code to a compiler and letting it find the bug.

I’ve run bcachefs as my desktop root filesystem for a couple of years now.

A few years ago I was CTO of Mozak, and we built a RISC-V zkVM: write Rust (or anything that compiles to RISC-V), run it, get a zero-knowledge proof that it ran correctly.

The original puzzle, preserved on the Internet Archive: Decrypting the Two-Time Pad — scroll down past the other puzzles to find it.

A zero-knowledge VM makes one promise to a verifier: I ran the program whose hash is H, on this input, and got this output, and here is a proof you can check without re-running anything.

My property-testing engine for base_quickcheck had a global.

Here is a line from base_quickcheck that surprised me: (* shrinker.ml *) let int = atomic atomic means “never produce any shrink candidate”.