Mahiro Hirakawa

Independent. Local-first developer tools, and a verification substrate for effects that have to be undoable. Rust. Limits written down before features.

Tokyo, Japan Joined on May 18, 2026 https://glovrex.com

Mahiro Hirakawa

Aug 30

The undo has to exist before the write does

#showdev #rust #ai #security

8 min read

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Mahiro Hirakawa

Jul 11

ime bugs, display-width bugs, and bidi bugs are the same bug

#debugging #frontend #javascript #webdev

4 min read

Mahiro Hirakawa

Jul 9

Output is cheap now. Keep the receipts.

#discuss #ai #productivity #career

4 min read

Mahiro Hirakawa

Jul 4

Teaching a grader the difference between pаypаl and paypal

#unicode #i18n #opensource #machinelearning

4 min read

Mahiro Hirakawa

Jul 3

a width check said the string was safe to cut. it split a kanji in half.

#javascript #unicode #i18n #webdev

7 min read

Mahiro Hirakawa

Jul 2

The Enter key that submits your form while a Japanese user is still typing

#javascript #i18n #testing #webdev

5 min read

Mahiro Hirakawa

Jul 2

Three ways CJK text breaks big open-source projects, over and over

#i18n #opensource #javascript #webdev

6 min read

Mahiro Hirakawa

Jul 2

The Sandwich Test: How I Check If A Dev-Tool Idea Is Actually Winnable Before I Build It

#devtools #startup #opensource #indiehackers

5 min read

Mahiro Hirakawa

Jul 1

How this page breaks Japanese lines

#cjk #typography #javascript #webdev

2 min read

Mahiro Hirakawa

Jul 1

The Enter key that fires while you're still typing

#cjk #ime #javascript #webdev

3 min read

Mahiro Hirakawa

Jun 30

I cataloged 93 CJK and Unicode bugs in open source. Most are the same five mistakes.

#opensource #i18n #javascript #webdev

5 min read

Mahiro Hirakawa

Jun 29

A searchable corpus of CJK and Unicode bugs in open-source libraries

#japan #i18n #webdev #unicode

4 min read

Mahiro Hirakawa

Jun 29

Your main input handles IME composition. The rename box next to it doesn't.

#javascript #react #i18n #a11y

4 min read

Mahiro Hirakawa

Jun 28

Japan-readiness is a cliff, not a gradient: what 92 dev tools' front doors actually look like

#japan #localization #saas #devtools

6 min read

Mahiro Hirakawa

Jun 28

I find Japan-shaped holes in global software

#javascript #i18n #react #webdev

4 min read

Mahiro Hirakawa

Jun 28

how to build a CJK/IME regression suite for a terminal or editor app

#testing #i18n #ai #japanese

5 min read

Mahiro Hirakawa

Jun 28

I tested whether AI coding agents break on Japanese input

#ai #opensource #i18n #japanese

3 min read

Mahiro Hirakawa

Jun 28

the bugs that only break in Japanese (and how to find them in someone else's repo)

#opensource #i18n #japanese #webdev

3 min read

Mahiro Hirakawa

Jun 28

the bug a merged fix forgot: how i find first OSS contributions that actually merge

#opensource #beginners #github #tutorial

5 min read

Mahiro Hirakawa

Jun 28

I scanned 15 funded developer tools for Japan-readiness. Every one scored F.

#japan #i18n #webdev

2 min read

Mahiro Hirakawa

Jun 28

The Japan-readiness Standard

#japan #i18n #webdev

3 min read

Mahiro Hirakawa

Jun 26

the same few bugs keep hiding in libraries you already trust

#opensource #debugging #programming #webdev

6 min read

Mahiro Hirakawa

Jun 26

"Personas vs. tool-scoping: where I landed differently from gstack"

#claudecode #ai #agents #productivity

3 min read

Mahiro Hirakawa

Jun 26

"Read-Only Reviewer Agents Catch What Your Main Agent Waves Through"

#claudecode #ai #productivity #opensource

4 min read

Mahiro Hirakawa

Jun 26

"Your Repo Is the Memory. Your Model Is the Worker."

#claudecode #productivity #ai #webdev

4 min read

Mahiro Hirakawa

Jun 26

"I Found ~30 Mergeable OSS Bugs in a Day. They Were All the Same Shape."

#opensource #productivity #claudecode #webdev

3 min read

Mahiro Hirakawa

Jun 26

Stop using the model as your memory

#ai #claudecode #agents #productivity

3 min read

Mahiro Hirakawa

Jun 25

I built a Reddit reply-bot to find posts worth answering. Then I deleted the part that posts.

#opensource #indiehackers #ai #webdev

3 min read

Mahiro Hirakawa

Jun 25

Your AI-tool usage is invisible. Here are 4 tiny local tools to see it.

#claude #ai #opensource #productivity

5 min read

Mahiro Hirakawa

Jun 25

What I learned shipping 4 Japanese-i18n PRs into real OSS as a faceless 19yo

#opensource #i18n #beginners #career

5 min read

Mahiro Hirakawa

Jun 25

I scored 40 dev tools on Japan-readiness. 0 of 40 have a Tokushoho (特商法) page.

#japan #devtools #localization #i18n

2 min read

Mahiro Hirakawa

Jun 24

I built 128 things with AI. 127 are dead. So I started shipping into real OSS instead.

#opensource #japan #buildinpublic #webdev

2 min read

Mahiro Hirakawa

Jun 22

I built 128 things with AI in 4 months. Then I made an AI dissect all of it.

#ai #buildinpublic #career #productivity

3 min read

Mahiro Hirakawa

Jun 20

I built a 5-second CLI to check if your site is ready for the Japanese market

#japan #cli #webdev #opensource

2 min read

Mahiro Hirakawa

Jun 20

The Enter key that quietly breaks Japanese input (and how to test if your app does it)

#japan #i18n #webdev #a11y

2 min read

Mahiro Hirakawa

Jun 20

Where foreign dev-tools quietly lose the Japanese market — and a free index to check your own

#i18n #opensource #saas #japan

4 min read

2 Week Community Wellness Streak

1 Week Community Wellness Streak

Writing Debut

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