Netlify is ripping out the sandboxing tech behind its Edge Functions and swapping it for Firecracker, the microVM system Amazon built to run Lambda.
Netlify announced it has moved Edge Functions off V8 isolates - the lightweight JavaScript sandboxes that Cloudflare Workers popularized - and onto Firecracker microVMs. The company says the change makes functions run up to five times faster. Firecracker is the virtualization tool AWS open-sourced in 2018 to isolate Lambda and Fargate workloads without the overhead of a full virtual machine. Netlify frames this as a rebuild of how its edge platform executes code, not a routine optimization pass.
Isolates and microVMs solve the same problem - start code fast while keeping tenants isolated - through different tradeoffs, and that tradeoff has quietly split the edge computing market. Picking Firecracker means Netlify is betting that stronger isolation and steadier performance under load matter more to developers than the ultra-thin cold starts isolates are known for.
Cloudflare built much of its Workers pitch on V8 isolates beating microVMs on cold-start speed. Netlify's numbers suggest that gap has narrowed enough to make the opposite architecture worth switching to.