YU-KI

Founder of Ark Co., Ltd. (Tokyo). Building indie tools solo — a Chrome extension that turns your mouse pointer into your pet, a task manager, and a crime-prevention app (in progress). Sharing the build process, marketing experiments, and lessons learned along the way.

Social Links

Recent activity

I spent two years building things nobody used. This time I'm stopping at v0.2.0.

Link rot is quietly an attribution problem, not just a broken-link problem

Maybe we don’t have a productivity problem. Maybe we have a context problem.

Building an AI product taught me that the LLM isn’t the hardest part

Early signal from Cask: people respond more to “planning is exhausting” than to “curated bars”

I spent two years building things nobody used. This time I'm stopping at v0.2.0.

Link rot is quietly an attribution problem, not just a broken-link problem

Maybe we don’t have a productivity problem. Maybe we have a context problem.

A chat assistant that runs your server so you don't have to live in the terminal

Built a free AWS alert audit tool - zero real users so far, would love your eyes on it

A chat assistant that runs your server so you don't have to live in the terminal

Two customers almost booked the same appointment slot in my SaaS. Here's the one-line bug that caused it

Two customers almost booked the same appointment slot in my SaaS. Here's the one-line bug that caused it

I built Lumshot, a modern screenshot and visual communication tool for Windows

A chat assistant that runs your server so you don't have to live in the terminal

A chat assistant that runs your server so you don't have to live in the terminal

Built a free AWS alert audit tool - zero real users so far, would love your eyes on it

32 commits later, the biggest improvement wasn't technical

Two customers almost booked the same appointment slot in my SaaS. Here's the one-line bug that caused it

5% churn at $3k MRR is $150. At $20k it's $1,000. Nothing about the product changed.