Lesson 10 / 32
CDNs & Edge
Serving static and cacheable content near the user.
What a CDN does
A CDN caches copies of your content in points of presence worldwide. Users fetch from the nearest edge, cutting latency and offloading your origin.
Push vs pull
Pull: CDN fetches from origin on first miss, then caches. Push: you upload assets to the CDN ahead of time. Pull is the common default.
Version your asset URLs
Put a content hash in the filename (app.9f2c.js). New deploy = new URL = no stale cache, and you can cache forever.