Black Cat Notes

I’m Kuroneko — building in public. After years working with Japanese companies across manufacturing and IVD for the China market, I pivoted into AI and indie making to ship practical, calm software.

Here I share short takes on AI/product, notes from hands‑on work, and experiments in AI productization, iOS apps & small games, Rust tools, and Python data plumbing. Learn more on my About page.

Recent Posts

• Three Workflows I Tried to Improve Codex Front-End Aesthetics

  24 Mar, 2026

  I compared three practical ways to get better front-end design out of Codex—from no skill, to OpenAI’s frontend skill, to Stitch MCP—and then checked how Claude Opus 4.6 stacked up.

• Codex Subagents Just Got Much Better. Custom Agents Are Finally Worth Trying.

  17 Mar, 2026

  The latest Codex App update makes subagents far more visible and steerable. The real win is that custom agents are finally practical to observe, tune, and use in everyday workflows.

• SentenceDeck Is Live on the App Store

  3 Mar, 2026

  SentenceDeck turns any sentence into natural speech for language practice — with two TTS engines, local storage, and a pay-as-you-go credit system.

• Simple Warm Reminder 3.0: Dark Mode & 14 Languages

  27 Feb, 2026

  Version 3.0 adds Dark Mode and 10 new European languages — designed for calm, accessible reminders in any lighting.