GitHub Zenn dev.to X

日本語 Contact

reliability · incident response · SLO · safe change

Reliability for systems that have to keep working.

I embed with teams as an SRE to keep their systems running. Incident response, SLOs, and safe change are the day-to-day.

Read the work →See the OSS

Zenn

SRE fieldwork, written up in Japanese.

Concrete write-ups of the incident response, SLO and safe-change work I do on client systems.

When Data Marts Proliferate and the Vendor Sends a Cost Increase Notice2026-06-15↗Why It Is Hard to Decide on Refactoring Proposals2026-06-01↗When Chasing Incidents, Experiences Fade Away2026-05-26↗Why Your Team Is Not Acting Even When SLOs Are Configured2026-05-25↗When Teams Fear Releases, There Is a Hidden Bottleneck No One Calls a Problem2026-05-18↗Stalled Schema Migrations in a 24/7 SaaS: Breaking the Three-Month Impasse2026-05-11↗

Tools

Tools I wanted on the ground, built as open source.

A personal OSS effort. I build what I need and open-source it to make SRE better for everyone.

Real-time PostgreSQL incident dashboard for the critical first 30 seconds.

Find the real column references before you touch a Rails/Django schema.

Fast Markdown link & structure linter to keep docs from rotting.

tinytapC · eBPF

Kernel-level traffic visibility, built on eBPF.

the full toolbox on GitHub

dev.to

OSS I built, problems I hit, libraries worth reading.

How my tools work and why I built them. Coding problems I ran into and what I did about them. Code-reading notes and tips on the open source I use every day.

How I Designed a Go Linter's Rule Engine So Adding a Rule Is One Line2026-07-14↗Tired of re-recording my README demo GIF by hand, I turned the whole demo environment into code2026-07-07↗Couldn't you just use pg_activity? — staking out one corner of Postgres incident triage2026-07-01↗The first 30 seconds of a Postgres incident: why they take 30 minutes2026-06-23↗How to safely remove a Rails column: finding every real reference before you delete2026-06-16↗Renaming `user` when grep can't tell which model you mean2026-06-09↗

Consulting

Let's talk reliability

Incident response, SLOs, safe change, observability. If something around the reliability of a long-running system is weighing on you, tell me what's going on. I start by getting a clear read on where things actually stand.