Vercel folded builds, sandboxes and functions onto one compute layer running 25 million sandboxes a week.

Fluid absorbs every workload shape onto a single mechanism, currently carrying over 15 million builds a day and a trillion requests a month (Vercel). Underneath is Hive, provisioning a full VM in milliseconds with filesystem state included, giving isolation stronger than an isolate without container startup cost. Billing is Active CPU, so you pay only while code runs, not while it waits on a database or a model call. That pricing shape is what makes long-idle agent workloads affordable, and it's the detail to copy if you're building anything that sits waiting on tool returns.