Koka
I solve problems.
Skills
Engineering Management
Led cross-functional teams across backend, mobile, and web.
Built repeatable processes from project kickoff to stable release cycles—fast enough to ship, flexible enough to experiment.Rust
Rust is my first choice for personal work. Contributed to rust-lang/clippy;
built a hobby kernel, interpreter, and algorithm solutions on AtCoder(Highest 1201).Ruby
Ruby is my go-to for backend at work. Shifted from Capistrano to AWS ECS for deployment.
Focused on balancing speed with confidence: built out automated tests, introduced type checking (Steep/rbs-inline), and added CI checks to catch N+1 queries introduced by pull requests etc.JavaScript/TypeScript
Used to work with Vue.js/Nuxt.js, now mostly React. I use Next.js, Astro, or Vite depending on the project.
For state management, usually jotai or nuqs. Styling with Tailwind, often with shadcn.Python
Researched text summarization at university — back before LLMs, right when "Attention Is All You Need" dropped.
Implemented Attention mechanisms and Encoder-Decoder models; have a solid grasp of Transformer fundamentals.
I've been using claude_agent_sdk to throw unreasonable tasks at AI these days.
Also wrote some content for track and CODEPREP.Infra
Managing AWS infrastructure with Terraform. Most common patterns I set up: CloudFront + S3 / ECS Fargate / Amplify・Lambda
Development Environment
✱ Claude Coding...> with Mac(work) / Arch Linux + i3wm + tmux + zsh + Neovim
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Side Projects
Automatic-control system for UAV(Unmanned Aerial Vehicle, a.k.a Drone)/archived
- written in C(+ inline asm)
- in-time object recognition in movies from UAVsAir Conditioner Controller using Infrared Sensor with Raspberry Pi Zero
- repaired a broken controller with SIR-34ST3F IR device
- written in MicroPythonRunix, a Hobby Kernel in Rust
- boots on qemu
- accepts keyboard input
- supports 64bits mode and multi-boot
- recovers from at most double fault
- GitHubLox Interpreter in Rust
Loxr, a tree-walking interpreter for the Lox language based on "Crafting Interpreters."
Covers the full pipeline — lexer, parser, AST evaluation — with closures, classes, and getter/setter support. Also compiled it to WebAssembly so it runs in the browser.
- miette/thiserror
- tracing
- wasm-bindgen
- GitHub
- GitHub Pages(Wasm demo)Marmoset, a Toy Interpreter in Rust
- write a tiny interpreter referring Writing An Interpreter In Go
- GitHub