The DOTS project used for the presentation Converting Your Game to DOTS and contains an example of how DOTS could be used to replace a low performance process in your games (shooting many bullets at once, in this case). This is meant to provide a simple, targeted example. A video presentation of this project can be seen here
I merely took the existing project and updates the DOTS implementation to be compatible with Unity 2020.3
If enemies and bullets aren't rendering, add scripting define symbol: ENABLE_HYBRID_RENDERER_V2 to your project.
NOTE: These shaders wont work on Unity 2021 as of published date.