Validate Every Change, Deploy Only from main: Jekyll + GitHub Pages
How a historical Jekyll site used GitHub Actions to validate every branch and pull request while reserving production publishing for changes merged to main.
Builder · Researcher · Explainer
Systems, AI, research — built and explained with evidence.
I build and study local AI infrastructure, agent systems, software, security, mathematics, and data-driven research. This site is the durable record of the systems, experiments, failures, and ideas worth explaining.
Featured engineering story
I Let AI Agents Run a Nationwide CTF. The Hard Part Wasn't Solving the Challenges.
I review the AI-agent pipeline I used at Japan's Ministry of Internal Affairs and Communications nationwide CTF, separating the official 26th-place, 5,701-point result from local tracker data and documenting gaps in orchestration, state, verification, and observability.
26th place5,701 official points110 tracked challenges
Engineering
Systems & AI Infrastructure
Local inference, GPU/runtime experiments, agent orchestration, networking, and build logs.
Research
Data & Reproducibility
Statistical modeling, health data, methods, limitations, and reproducible analysis.
Foundations
Math & Algorithms
Careful explanations, proofs, algorithms, and a preserved archive of earlier work.
Latest
Recent writing
2026-10-02
BOJ 10803 — Making Squares: A Verified Recurrence Bound
Archived technical note: BOJ 10803 — Making Squares: A Verified Recurrence Bound.
Fast Fourier Transform (FFT)
A radix-2 FFT guide: DFT normalization, butterfly decomposition, polynomial convolution, and the limits of floating-point integer results.
BOJ 1199 — Euler Circuit
Archived technical note: BOJ 1199 — Euler Circuit.
Bolzano–Weierstrass Theorem
A proof that every bounded sequence in finite-dimensional Euclidean space has a convergent subsequence, with the compactness distinction.