Say things like custom workflow logic or custom data transformations. They might require an api call.
Performance-wise, it’s also very promising. For a simple hello world, the « cold start » (which is mostly compile time) is around 10ms, and on subsequent requests it runs in 1ms.
eta link: https://v8.dev/docs/untrusted-code-mitigations#sandbox-untru...
Edit:
> If you execute untrusted JavaScript and WebAssembly code in a separate process from any sensitive data, the potential impact of SSCA is greatly reduced. Through process isolation, SSCA attacks are only able to observe data that is sandboxed inside the same process along with the executing code, and not data from other processes.
I do run isolates in separate processes to prevent security issues, even if that may not be enough. Still an early prototype for now.
As long as you run each customer in a separate OS-level process, you should be good. But then, that is not much different from Lambda or other FAAS implementations.
> Workers are distributed among cordons by assigning each worker a level of trust and separating low-trusted workers from those we trust more highly. As one example of this in operation: a customer who signs up for our free plan will not be scheduled in the same process as an enterprise customer. This provides some defense-in-depth in the case a zero-day security vulnerability is found in V8.
[1] https://blog.cloudflare.com/mitigating-spectre-and-other-sec...
I have 3 products where I’d allow client code to run once we can make that happen.