Every dev has a piece of code they've never published

Mine is 8 years old It started with a WebView A client needed to open PDFs in the app Not critical, a one-off, WebView does the job, move on Next project, same ask. PDF, Word, Excel, open them in-app So I wrote a tiny native module QuickLook on iOS, system Intent on Android Nothing documented, just something that works And I carried it from client to client for 8 years Copied into every project, hand-adapted every time Never packaged, never published The kind of reliable code that lives nowhere but in your old repos It's the least talked-about thing in this job Every experienced dev has their private toolbox Modules that survived 5 companies, that work better than half the npm libs out there Sitting in repos nobody opens anymore This year I finally took one out of the drawer expo-quick-look, open source, MIT QuickLook on iOS, native Intent on Android, local file or URL, multi-file, thumbnails, markup 8 years between the first copy-paste and a clean v1 Demo video right below But the real point isn't my lib It's all that useful code we keep to ourselves and never share So tell me, what's yours? The module you've been copying for years and never dared to publish