Hacker News new | past | comments | ask | show | jobs | submit login

> No they don’t.

On the contrary, I developed early merchant and payment gateway tech, and they absolutely do. The scenario you describe is extraordinarily rare, which allows an arbitrage between CAP perfection and customer satisfaction.

On a separate note, at any given time, some parts of our national payments ecosystem are “down”. There are enough players involved you have an appearance of resilience.

You can see this in a mall, when one store’s card swipe terminals are down, and another’s are not, and almost never happens that all the stores are down at the same time.

You can think of all these other players as an incidental circuit breaker pattern upstream of Visa.

VisaNet itself is surprisingly unscaled, capable of only about 24,000 transactions per second. Twenty years ago, our gateway would hit 15,000 transactions per second real world use. To do that, we scattered/gathered across many independent paths into card networks and various merchant banks.



Guidelines | FAQ | Support | API | Security | Lists | Bookmarklet | Legal | Apply to YC | Contact