Back in college, 100,000 yen a month was my entire budget. Stacking side jobs, I got that up to 600,000 a month — then I was laid off and it went straight back to zero. Six months later, after building out an autonomous Claude Code setup, I'm at 1.2 million yen a month in revenue. Once the environment is right, the hours where "the system is running" outnumber the hours where you're moving your hands. This post takes apart one piece of that system.
Why this setup works
After a few days of touching dozens of files a day with Claude Code, it hits you: "the TypeScript check is running every single time, and the response keeps stalling."
If you wire up the default hooks in the obvious way, you end up calling Prettier on PostToolUse every time a file is saved, and the TypeScript compiler on Stop. It looks conscientious. In practice it's a pile of waste.
tsc takes 2–4 seconds just to start up.
