Despite the fact that Dynamics 365 is a highly customizable and flexible business application, there can be business requirements that can not be solved using the standard features. Fortunately, there are several possibilities to extend functionality using custom code, enabling programmers to develop specific functionality to fulfill the business needs. I’m an experienced programmer in Dynamics 365 using the following techniques.


Using JavaScript, the client side of the application can be extended. This includes custom development for the user interface, for example to change layout and show notifications or messages. JavaScript can also be used to make client-side webservice calls, to trigger actions within Dynamics 365 or even external applications.


As Dynamics 365 is a web-based application, it can be extended using HTML and CSS. For example: custom HTML pages can be developed to show data in a specific layout.


Using .Net code (C#), custom workflows and plugins can be developed that extend Dynamics 365 on the server side. This means that the code is executed by the server. This enables developers to program custom business logic that is always executed, independently from user interaction. This can vary from simple calculations to complex data-flows.

Please note: not all customizations that can be added using custom code are automatically supported by Microsoft! That means that when unsupported code is used, it can break when Microsoft updates the application. It’s recommended to always only use supported code.