Private service endpoints in isolated virtual networks

A system, comprising:

• one or more computing devices;
• wherein the one or more computing devices include instructions that upon execution on or across the one or more computing devices:
• provide, via one or more programmatic interfaces of a cloud computing environment, to a first client of the cloud computing environment, an indication of a particular service which is implemented at least in part at one or more resources of a second client of the cloud computing environment at a first premise external to the cloud computing environment;
• transmit, from a first virtual network established for the first client at the cloud computing environment, to a second virtual network established for the second client at the cloud computing environment, a service request directed to the particular service, wherein the service request originated at a resource of the first client at a second premise external to the provider network;
• and
• transmit, from the first virtual network to the resource of the first client, a response to the service request, wherein the response is generated at the one or more resources of the second client at the first premise, and wherein the response is received at the first virtual network via the second virtual network.

One or more non-transitory computer-accessible storage media storing program instructions that when executed on or across one or more processors:

• provide, via one or more programmatic interfaces of a cloud computing environment, to a first client of the cloud computing environment, an indication of a particular service which is implemented at least in part at one or more resources of a second client of the cloud computing environment at a first premise external to the cloud computing environment;
• transmit, from a first virtual network established for the first client at the cloud computing environment, to a second virtual network established for the second client at the cloud computing environment, a service request directed to the particular service, wherein the service request originated at a resource of the first client at a second premise external to the provider network;
• and
• transmit, from the first virtual network to the resource of the first client, a response to the service request, wherein the response is generated at the one or more resources of the second client at the first premise, and wherein the response is received at the first virtual network via the second virtual network.