The point about VMs being the wrong shape because they’re tied to CPU/memory resonates hard. The abstraction forces you to pay for time, not work.

I ended up buying a cheap auctioned Hetzner server and using my self-hostable Firecracker orchestrator on top of it (https://github.com/sahil-shubham/bhatti, https://bhatti.sh) specifically because I wanted the thing he’s describing — buy some hardware, carve it into as many VMs as I want, and not think about provisioning or their lifecycle. Idle VMs snapshot to disk and free all RAM automatically. The hardware is mine, the VMs are disposable, and idle costs nothing.

The thing that, although obvious, surprised me most is that once you have memory-state snapshots, everything becomes resumable. I make a browser sandbox, get Chromium to a logged-in state, snapshot it, and resume copies of that session on demand. My agents work inside sandboxes, I run docker compose in them for preview environments, and when nothing’s active the server is basically idle. One $100/month box does all of it.