Current_rpcmodule Job : sig ... endClient-side API to contact a job service.
module Engine : sig ... endClient-side API to contact an engine service.
This is used on the server-side to provide access to the OCurrent Engine. Create an instance of the functor with module Rpc = Current_rpc.Impl(Current). We use a functor here just to avoid having Current_rpc depend on Current, which would be annoying for RPC clients.