If you already have a single server that includes all backend features, you have a monolithic service, even if you start two or more instances of this service. A monolithic service has a few disadvantages—it is impossible to scale vertically, it is impossible to update and deploy one feature without interrupting all the running instances, and if the server fails, it affects all features. Let's discuss these disadvantages a little further. This might help you to convince your manager to break your service down into microservices.