Testing stubs are often setup by developers within a project. They provide a good way to simulate a system which is too complex, too costly or otherwise impractical to reproduce for testing.
The problem with stubs tends to come after a project has moved on, who looks after the stub? Often users of the stub are left trying to figure out how to fix them when they fail or going cap in hand to another team to fix for them.
With stubs being spread across many different technologies and implementations it can becomes a headache to maintain.
What's required is a central application designed for stubbing out various systems and technologies. One that is simple to use and maintain and one that's feature rich in terms of simulation. One that can stand up to a high level of load to use with performance testing and fully scaled environments.
Current tools seem to be focused on the functional side of stubbing. Looking at the market today such a performance related solution doesn't exist.... until now. Software Consult has developed such a stub, it will emulate most HTTP/HTTPS services simply and effectively.
See here for more details Performance Stub