Cloudflare Workers & the Edge
Workers run your JavaScript within milliseconds of every user on earth — no containers, no cold starts, no servers to patch. This course takes the platform end to end: the fetch-handler programming model built on web-standard Request and Response, the wrangler dev loop with environments, secrets, and bindings, KV and the Cache API for fast reads, D1 and Durable Objects for real state, and a production deploy with routes, observability, and gradual rollouts. The programming model is plain JavaScript, so every challenge runs live as you read.
5 lessons · ~2 hours
1. Compute at the Edge
The Workers runtime
A Worker is an exported object with a fetch handler — web-standard JavaScript running in V8 isolates, which is why cold starts barely exist.
Wrangler & the dev loop
wrangler config declares what your Worker needs, wrangler dev runs it locally, and everything the platform gives you arrives through one door — the env bindings object.
KV & caching
Workers KV is a global, eventually consistent key-value store; the Cache API is per-data-center HTTP caching. Knowing which to reach for is half the skill.
State at the edge
D1 gives you SQLite with prepared statements; Durable Objects give you a single coordinated instance with in-memory state and storage. Different problems, different tool.
Going live
wrangler deploy ships worldwide in seconds — then the real work is domains, observability, knowing your limits, and rolling out new versions gradually.