TL;DR: The thing that finally broke me with Dexcom Clarity was discovering that you can export your data — but only as a PDF. Not CSV, not JSON, not anything a developer could actually use. 📖 Reading time: ~38 min What's in this article The Problem: CGM Apps Are Either Locked Down or Ugly What You'll Actually Build Project Setup — From Zero to Running Locally Connecting to Glucose Data — Your Options and Their Tradeoffs Firestore Data Model — Get This Wrong and You'll Rewrite It Real-Time Updates with onSnapshot — Where It Gets Interesting Building the Glucose Chart with Recharts Firebase Auth — Keeping Your Health Data Actually Private The Problem: CGM Apps Are Either Locked Down or Ugly The thing that finally broke me with Dexcom Clarity was discovering that you can export your data — but only as a PDF. Not CSV, not JSON, not anything a developer could actually use.…