> if there is an API you don't need MQ, or will you make a front MQ for every API you're calling ? I don't think this is quite right. An API might use a messa

> if there is an API you don't need MQ, or will you make a front MQ for every API you're calling ? I don't think this is quite right. An API might use a message queue as a transport mechanism. The MQ only gives you a way to communicate, it doesn't define how you structure your requests. in your payment example, if you replace MQ with REST, it gives you the same answer. Some message queues give you rich diagnostics for when messages fail. Others like NATS only give you the guarantee that the server will be up. MQs come in many flavours. some act like python's Queue, but allow you to use many machines. Some are as you say, a buffer. However I like to use them for connecting n transient instances of a service to an API front end. The routing is handled for you, and you can isolate services from each other.