The latency to query a central database should be under 100 mS from anywhere in the country. There's no reason it couldn't be done properly today. But ATM syste

The latency to query a central database should be under 100 mS from anywhere in the country. There's no reason it couldn't be done properly today. But ATM systems were architected in the late 70s and they depend on a network of regional data centers that reconcile nightly.