Cloudflare Workers — when to bet your stack

Workers run JavaScript at the edge in 200+ datacenters. Latency drops, cold starts disappear. Hidden costs and pitfalls.

Cloudflare Workers run on V8 isolates, no container per request. Cold start under 5ms. Free tier: 100k requests per day.

Where it shines: API gateways, A/B testing, image transforms, auth middleware, edge caching with logic.

Where it fails: long-running jobs (over 30s on paid, none on free), heavy CPU like ML inference, anything needing native modules. Workers KV is eventually consistent — surprises if you assume strong.

Pricing past free is fair: $5/mo for 10M requests. Beats Lambda for short tasks. Worse for over-100ms work.