Run-Time Compilation
If you have created an extension for a business logic controller or a data access class in a customization project, during the project publication, the MYOB Acumatica Customization Platform stores the code of the class extension in a .cs file within the App_RuntimeCode folder of the website.
At run time, the platform compiles the code in a separate library that is dynamically merged with the original classes. Run-time compilation is used by default for the code of the DAC and Code project items. (See Types of Items in a Customization Project for details.)
Publication of a customization updates the files in the App_RuntimeCode folder of the website. Unlike when the Bin folder is updated, update of files in the App_RuntimeCode folder doesn't cause the application domain to restart. (See Project Publication: General Information for details.)