docs/manual/source/start/customize.html.md
When you download an engine template, it comes with the source code. All engine templates follow the same DASE architecture and they are designed to be customizable.
You may want to customize an engine for many reasons, for example:
To learn more about DASE, please read "Learning DASE".
After you have finished modifying the code, you can re-build and deploy the engine again with:
$ pio build; pio train; pio deploy