alt Hacker News> Walmart is currently trialing it to save $3B-$7B a year in interchange fees. No crypto, just XML messages through a mainframe at the Federal Reserve with a 20 second SLA.
Please tell your user that this SLA is much too high for many purposes. A cafe or such would lose a ton of money if every transaction took 20 seconds longer to conduct.
Replies
toomuchtodo • yesterday at 9:25 PM
Works fine based on the evidence. It’s a maximum SLA, not every transaction. The economics are too compelling to ignore. Fast enough.
It's the worst case before they get penalized. I've had worse times with Mastercard and Visa. It's really not a big deal if one in a thousand payments, you sit by the card reader for 30 seconds before it says "please try again".