_{今日山色 · 2026-11-01 · a new ink landscape every morning, seeded by the date  ·  「寒灯思旧事，断雁警愁眠。」 杜牧}

Hi, I'm jk.

Software engineer. I work on billing and growth infrastructure — the plumbing that turns usage into revenue — and on making engineering teams faster with AI agents.

Languages	Go · Python · TypeScript · Rust
Ground	Kubernetes · Postgres · Stripe · Cloudflare
Thinking about	agentic engineering, the economics of AI products
Home	defiabell.com — 听风的小世界, a little archipelago of writing, projects and games; everything I make lives on a subdomain of it

_{About the painting}

_{Drawn from scratch every morning by a GitHub Action, with the date as the random seed — value-noise ridgelines, layered washes, one red sun. Same day, same picture; tomorrow, a new one. It is the same painter that draws the header of 听风闲语.}