A good example of such a feedback loop are computers. It is impossible to think of modern physics without them, on the experimental side at least.

Another example are computers themselves. You can't build computers without computers, so they are already kind of building themselves, with us humans using as evolutionary slaves/hosts.

Computers are involved in the practical side of modern physics, but not in the conceptual side. When it is demonstrated that an algorithm will produce a trust-able result, no reference is made to any "real" aspect of computers. Instead, the algorithms are designed based on symbol manipulation and could just as well be carried out by a platonic physicist writing notes in the Mediterranean sand. The specific details of how computers are actually made impacts the implementation but not the results.