How Encore got Firecracker microVM builds running on Apple Silicon
Encore's production builds have run in Firecracker microVMs since 2022, but Firecracker needs /dev/kvm, which no Mac has. So the team built crackling, a microVM API that drives Firecracker on Linux and Apple's Virtualization.framework on Macs, booting identical images on both. The hard part: converting Docker layers into a bootable block device, a problem no existing tool solved.