Generally speaking, it's the lack of a linear service bus and orchestration. In a 'traditional' SOA architecture, the workflow is defined as a linear progressi

Generally speaking, it's the lack of a linear service bus and orchestration. In a 'traditional' SOA architecture, the workflow is defined as a linear progression from one state to another, where each 'service' mutates ( or not ) the state of the data. Determining 'which' services are used/called in the service bus is typically defined in an orchestration. They definitely have some similarities, however one thing to note about 'Architecture' is that it's often more about ways of thinking about a problem as much as it is about 'solving a specific problem'. Another helpful comparison might be: SOA is like GNU Hurd and Micro-Services are like Unix.