The only place there is a failure here is on the management level on both sides. Any kind of certification in this space have you have the following for develo

The only place there is a failure here is on the management level on both sides. Any kind of certification in this space have you have the following for developing core functionality regarding financial data: * Proper definition of hard requirements and acceptance tests. * Developers have to develop and write tests against this specification. * Another developer have to perform a review and sign off that this code indeed lives up to this specification. * QA will run tests that verify the specification is met, and sign off that it met specification. That is a PM/PO that have responsibility for the specification. At least two developers and a QA person that have verified that the specification was met. A bug like this only goes live due to impossible to meet deadline or incompetency on multiple levels. The only remotely acceptable explanation would be that this is the result of some really weird edge case or possibly race condition. But in that case we're back to incompetency, since no experienced developers should design financial software without well known patterns and technologies for the core of the application. In this particular domain there is zero excuse for a bug like this.