# Leon Heuer

> Personal portfolio of Leon Heuer, a full-stack developer and dual computer science student from Germany. The site presents his background, software projects, academic publications, and contact options.

Leon Heuer has been programming since the age of 10. He develops server-side Minecraft mods with Kotlin and MongoDB, works with TypeScript and React on the frontend, and has used Rust professionally for backend development. He is doing a dual study programme in applied computer science at OTTO (https://www.otto.de/), Germany's second largest online retailer, working in full-stack development. In his free time he develops server-side mods for the Minecraft server SkyCave (https://github.com/skycavemc), used by thousands of players.

## Projects

- [My portfolio](https://github.com/heuerleon/portfolio): This portfolio website, built with TypeScript, Next.js and SASS/SCSS.
- [osu!backup](https://github.com/heuerleon/osu-backup): GUI-based backupper for the game "osu!", written in C#. Exports local player data and imports it on another machine.
- [SkyCave Island System](https://github.com/skycavemc/island-system): Island system for the Minecraft server SkyCave, written in Java with MongoDB. Creation and management of protected islands with regions and members.
- [SkyCave JobSystem](https://github.com/skycavemc/JobSystem): Kotlin plugin for the Minecraft server SkyCave, providing jobs with different advantages.
- [MC GUI API](https://github.com/heuerleon/mcguiapi): Java API for creating graphical user interfaces using inventories in Minecraft.

## Publications

- "Functional State Machines in Rust: Typestate and Newtype Patterns (Experience Report)" (Workshop paper, Jun 2026, with Falk Woldmann Lu and Jan Haase, DOI 10.1145/3830438.3830958): https://doi.org/10.1145/3830438.3830958 — Three case studies from production code on the effects of the typestate and newtype design patterns on code quality in Rust.
- "Benefits of Applying Software Design Patterns to Backend Rust Applications" (Bachelor's thesis, Feb 2026, arXiv:2607.02744 [cs.SE]): https://doi.org/10.48550/arXiv.2607.02744 — Case study on how the typestate and newtype design patterns affect software quality and compile-time enforcement of invariants in production backend Rust applications.

## Contact

- Email: leon@heuer.ovh
- Discord: @haku2
- GitHub: https://github.com/heuerleon
- LinkedIn: https://www.linkedin.com/in/leonheuer/
- Instagram: https://www.instagram.com/heuerleon/