We are a German software company building dependable products and open-source developer tools across TypeScript, Rust, and AI. We like difficult technical problems, explicit trade-offs, and software whose claims can be checked in its code, tests, benchmarks, and documentation.

Open source shaped our careers. Today, we maintain the tools we wish existed: focused libraries, native engines, and practical infrastructure for developers and AI agents.

• Dalo — one source of truth for the skills your AI agents run, with versioned sources, approvals, conflict handling, drift detection, and deterministic synchronization.
• Palamedes — open-source internationalization tooling for TypeScript applications, with a Rust-native toolchain and first-party framework integrations.
• Ferrocat — a Rust-native translation catalog engine for parsing, updating, auditing, reviewing, and compiling localized product copy.
• Ferromark — secure Markdown-to-HTML for Rust and Node.js, with full GitHub Flavored Markdown support and reproducible benchmarks.
• Ferroni — a pure-Rust Oniguruma-compatible regular-expression engine and multi-pattern scanner, built without a C toolchain.
• Sebastian Software Skills — open-source skills that turn repeated professional practice into explicit workflows for capable AI agents.

Open source is where we share our engineering work. Consulting is how we help teams apply that depth to products that need to last.

• Explore our open-source work — production-grade projects across developer tooling, libraries, native Node.js bindings, AI, and data formats.
• Work with Sebastian Consulting — two senior architects for React, TypeScript, frontend architecture, internationalization, performance, and platform work. No juniors and no hand-off to third parties.
• Browse all repositories — current work, experiments, and the archive.

We build in public when we can. Issues and pull requests are welcome in the repository they belong to.