Hi to dear IT people,
I am sure no reader missed the growing trend of microservices
The fact is that like any other new trend, there are many views of what exactly are microservices.
From my perspective, the microservices are the ultimate Object Oriented Design.
I would like to take the perspective of microservices API's. The fact that microservices expose themselves as API's, drives the rival about ESB or not.
As in any technical discussion, nothing is right or wrong and each tool has the features and specialization that was the motivation to create it.
With ESB, the motivation was to make protocol adapters, data transformation, service orchestration and more, out-of-the-box as much as possible, thus, reduce time to deployment.
When the IT will all be microservices, there would be only 1 protocol (currently RESTFull, who can tell what next).
The data of each microservice will be according to the business functionality.
Orchestration will still be required when few microservices would be called in a sequence with data split/merge, exception handling, contingency steps and more.
So, the only thing left to decide is how to do orchestration?
That could be answered by many technologies and platforms that one of them is ESB.
There are "half way" tools like Data Virtualization that may be suitable for some orchestration.
At the immediate time, until all IT will be microservices, you will still have legacy systems to integrate and once all your IT will be microservices you will face a new trend that will require different approach.
Bottom line is, ESB, BPM (or any other integration tool) is just a platform that looks at your IT as a cloud full of API's and does not care what system exposes it. Such platform can served you in past trends and will probably serve you in future trends.
That make sure the specific product you use is not too complicated so it become a challenge by itself.