Feature
FEATURED
FEATUREI Deleted All My Own Tasks — The Trap in "The Server Is the Truth" — Build Log #9
I recreated my account, logged back in, and everything was gone. The culprit was a safety check I wrote myself. It took minutes to realize there was nothing to restore from, and a few more to learn the free tier had no backups.
FEATUREApp Store Rejected Me for a Bug I Could Never Reproduce — Build Log #8
"Tapped the Terms link, nothing happened." But it opened fine on my own iPhone. The cause was that review devices are managed devices. Then, after passing review, I made a much worse mistake.
Build Log
FROM THE LAB
FEATURECutting My App's AI Cost by 90% — Build Log #5
The AI feature in my iOS app cost about ¥66 per heavy user per month. Switching models, turning web search off by default, and zeroing the thinking budget brought it to ¥6.8. Here's what I gave up to get there.
FEATUREMy Forced Update Reached Nobody — Build Log #6
The server said 'anyone older than this must update.' Users on old versions saw nothing at all. The cause was a design that waves you through whenever the check fails. Here's how I patched 13 generations of old builds to close it.
FEATUREThe Number I Hid From the UI Was Wide Open in the API — Build Log #7
My app's unit-cost figure was admin-only on screen. But the API had no admin check, so any logged-in user could fetch it directly. Closing it took one line. Realizing that a 401 doesn't prove anything took longer.
FEATUREApp Store Rejected Me for a Bug I Could Never Reproduce — Build Log #8
"Tapped the Terms link, nothing happened." But it opened fine on my own iPhone. The cause was that review devices are managed devices. Then, after passing review, I made a much worse mistake.