Rolling a Message Specification Update on a Message Broker (AWS SQS)

Message brokers facilitate communication between Message Publishers and Message Consumers. The instructions (fields) in the message are structured by the publisher of the message in a way the consumer can understand and parse without any problems. This mutual agreement is known to the developers, but not all projects externalize this agreement as a contract.

Just like we have API specifications (in different formats like Swagger), we ideally have to have Message specifications as well.  (These specifications are called event specifications in reactive solutions but the concept is the same) The message specifications should be externalized from the code, and be tracked in an SCM (Source Code Management) system like Git. This way, the specification can also be owned by the master of that source code repository and any feedbacks, change requests can be collected and handled by native functions of SCM (Pull requests, merge requests etc.). (I have seen companies using MS Excel for the same, but it is not easily manageable after some point). https://goo.gl/Bh3xfC