[nijave]

Pretty sure they invented Firecracker for Lambda. Iirc they were previously using a hot pool of EC2 instances behind the scenes with each customer getting their own instances and lambdas sharing capacity on an instance. Firecracker made it possible to spin up VMs in realtime instead of having spare capacity laying around.

That said, Fargate does kind of seem like a superior option

Edit: I guess this supports suspend and fast resume so invocation time should be somewhat better than Fargate.