Hi, I'm Jihoo.

I'm Jihoo — an undergraduate who lives and breathes systems-level code. My main languages are Rust, C++, C, and Astro, and I'm happiest when I'm deep in a compiler or poking around inside an operating system kernel. You can find me on GitHub.

My day-to-day setup is NixOS on both my desktop and laptop — the desktop runs GNOME, while the laptop runs niri and noctalia shell. Nix is more than a package manager to me; it's how I think about reproducibility and system design. Beyond that, I'm fascinated by compilers and language implementation, AI agents and how they're reshaping the way we write software, Lisp and its family of languages, and Cubical type theory — which sits at this beautiful intersection of type theory, homotopy theory, and constructive mathematics that I find endlessly compelling. Outside of code, I enjoy dabbling in philosophical thinking — nothing rigorous, just casual reading around East Asian traditions like Buddhism and Taoism, and lately Plato's ideas too. There's something about impermanence and non-duality on one side, and the theory of Forms on the other, that feels oddly resonant with how I think about types and computation.

I reach for an AI agent constantly while coding.

Right now there's a small stack on my desk — Cubical Type Theory, HoTT, and a category theory pdf — all patiently waiting for me to open them. I fully intend to. Any day now. In the meantime I have, somehow, found time for everything except that.

I ended up throwing in the towel on Owl, my old experimental cubical type theory proof assistant, and decided to just start over from scratch with Eagle — this time built around Cartesian cubical type theory, also written in Rust. Before diving back into the implementation, I'm planning to actually study type theory properly this time, instead of just winging it like I did with Owl.

On the OS side, I'm building KaguyaOS — a hobby OS written in Rust targeting x86_64 UEFI. It boots via UEFI with a GOP framebuffer, enforces ring 0/3 isolation with 25 system calls, runs a cooperative round-robin scheduler with SMP support, and has drivers for xHCI USB, NVMe SSD, and E1000 Ethernet. There's a FAT16 filesystem and a shell to tie it all together.