GeezerVison

Hey, I'm EY

Frontend developer working with PDFs in the browser. I write about PDF rendering and coding with AI agents on my blog (in Korean).

Building

300-page PDF viewer performance - Renders only the visible pages, so memory drops from 2.2GB to 30MB. (demo)
Saving and restoring PDF highlights - Saves a selected passage as coordinates and a quote, then finds it again in a revised PDF. (demo)
Box annotations in PDF coordinates - Stores boxes in PDF coordinates so they stay in place through zoom and rotation. (demo)
Full-text PDF search - Searches an index instead of the text layer and highlights every match, even a word split across a line break. (demo)
CDISC ODM study notes - Notes from 4 of us reading the ODM v1.3 spec, the clinical trial data standard. Written in Korean.

Contributing to

REA - Korean docs: added the Linux ps prerequisite to the README, corrected 32 FAQ translations, and fixed the skip-link label on 17 pages.
Archify - Diagram agent skill: gave default relationship labels readable contrast in light themes.
OpenEDC - Open-source EDC for clinical studies: added Korean localization.
MDN Web Docs - Korean translation: synced the <script> See also links with en-US, cleaned up 19 CSS pages with csssyntax macro errors, and clarified that Map.groupBy() shares the elements.
Vite Korean docs - Synced the per-environment and global hooks docs, aube and nub lockfile support in dependency pre-bundling, Environment API guide fixes, config file loading notes, and the top-level input option.
Paperclip - AI agent manager: kept the task board's horizontal scrollbar and column headers in view.
PDF.js - Text selection fix: shared selection listeners no longer stop working when the viewer that registered them is torn down.
zod - Reported two bugs with fix branches: Infinity missing from non-English "invalid type" messages, and z.union() inside .pipe() losing unrecognized_keys.
CDISC Conformance Rules Editor - Used a placeholder for a missing Rule ID in YAML export file names, and kept the last alert visible while the notification closes.
ODK Central - Data collection server: used the selected locale when comparing form names for duplicates.
UX/UI Agent Skills - Design agent skill: reported that measure_render and axe_audit exited 0 when skipped even with DS_REQUIRE_BROWSER=1, fixed in 2.9.10.