I used a robust web tool today to access an account of mine online. The company had spent millions on the interface, the functionality, dashboards, etc.
I tried to enter a new form of payment to use their services – error and crash.
There are lots of forgivable errors on a website or application. Make sure that taking your customer’s money isn’t one of them. These should part of the sanity checks you run everytime you release code. Don’t let anything go to production that stops a customer from paying.
Do you have sanity checks? Do they have the right things in them?