I implemented this in one of my past startup jobs. Basically a core banking system that implemented multiple roles of the system, including open banking. Depend

I implemented this in one of my past startup jobs. Basically a core banking system that implemented multiple roles of the system, including open banking. Depending on config, it would act as a bank, as an OB service provider, as an OB registry, as a merchant, etc. In addition, it was built in a way that instances, if allowed could talk to each other in 2 ways: 1. As part of the same entity, so you could scale your operation. 2. As part of an ecosystem, so you could for example create an entire open banking network or just a regular network with bank transfers and card payments using proper protocols such as ACH, ISO8583 and ISO2022 for example.