Apologies if I’ve misunderstood you (edit: I have) but assuming you are saying that 1ms to transfer funds between banks is ridiculously slow, why do you say tha

Apologies if I’ve misunderstood you (edit: I have) but assuming you are saying that 1ms to transfer funds between banks is ridiculously slow, why do you say that? Light travels about 300km in one millisecond in a vacuum, about 200km in optical fiber. The best achievable theoretical fiber optic RTT for NYC-LA is about 35-40ms. In practice 65ms+ is more realistic due to routing overhead and the fact that cables aren’t always laid in a great circle. This being a financial API with three parties involved in most transactions (the two banks and the fed clearinghouse) there is sure to be more than one round trip involved for TLS establishment, authentication, verification of funds and account availability etc, many of which involve traversing many inevitably complicated systems on each side. It would shock me if such a system could realistically target anything less than 500ms P50.