This eventually becomes a microservices vs monolith discussion though. Implementing both the message queue and the bank core integration service within 1 servi

This eventually becomes a microservices vs monolith discussion though. Implementing both the message queue and the bank core integration service within 1 service makes for less communication/network overhead and is easier to debug, which is definitely valuable. Seperating them out means you can use off the shelf products for the message queue and is easier to scale, which can also be valuable.