Given the mention of git clone from scratch, docker image downloads, and empty go build cache, I'm assuming the author meant "terminate" when saying shutting of

Given the mention of git clone from scratch, docker image downloads, and empty go build cache, I'm assuming the author meant "terminate" when saying shutting off, and "creating" when saying spin up or cold start. Using ASG Warm Pools would help quite a bit in the scaling performance, as start/stop is faster than create/terminate and maintains cache state between uses. If you want to optimize the create/terminate case, perhaps also create periodic snapshots of test instances after a run to populate the caches (or use something like Packer)