Introduction

Modular programming enables one to organize code into independent, cohesive modules, which can be combined to achieve the desired functionality. This allows us to create code that is:

• More cohesive, because the modules are built with a specific purpose, so the code that resides there tends to cater to that specific purpose.
• Encapsulated, because modules can interact with only those APIs that have been made available by the other modules.
• Reliable, because the discoverability is based on the modules and not on the individual types. This means that if a module is not present, the dependent module cannot be executed until it is discoverable by the dependent module. This helps to prevent runtime errors.
• Loosely coupled. If you use service interfaces, the module interface and the service interface implementation can be loosely coupled. 

So, the thought process in designing and organizing the code will now involve identifying the modules, code, and configuration files that go into the...