Other than the newer web tech initiatives like WebAssembly/JS sandboxing Yes, this is the lightest weight isolation that's somewhat secure for random code.. An

Other than the newer web tech initiatives like WebAssembly/JS sandboxing Yes, this is the lightest weight isolation that's somewhat secure for random code.. And considering that we regularly find exploits that escape that sandbox, I would never use it to run some random persons code on a server. Yes, we do that all the time in the browser, but that's a more limited environment where a single user is choosing what to run... whereas on a server, anyone who wants to attack the service can just upload whatever code they want. I know Cloudflare is doing it in Cloudflare Workers... and I think that's crazy. They're inspecting the code, and they added OS sandboxing... so that's a little better.. but trusting the JS sandbox in that environment is just nuts. Wouldn't surprise me if this ended up being another cloudbleed. If you want to run random code, the only safe option right now is to use a heavier form of isolation like a VM (and even that is not perfect). The performance loss is the necessary trade off to allow random people to run code (some of whom are deliberately attacking the service). This is the downside to the "cloud"... performance losses to allow random people to share servers.