That's the problem! It's really hard to find trustworthy sandboxing solutions, I've been looking for a long time. It's kind of my white whale.

As I understand it separate isolates in a single process are inherently less secure than separate processes (e.g. Chrome's site isolation) which is again less secure than virtualization based solutions.

As a TinyKVM / KVM Server contributor I'm obviously hopeful our approach will work out, but we still have some way to go to get to a level of polish that makes it easy to get going with and have the confidence of production level experience.

TinyKVM has the advantage of a much smaller surface area to secure as a KVM based solution and the ability to offer fast per-request isolation as we can reset the VM state a couple of orders of magnitude faster than v8 can create a new isolate from a snapshot.

https://github.com/libriscv/kvmserver

I imagine you messed about with Sandstorm back in the day?