Hi @Maxence_Fourrier 
First of all, Why do you use Webpack to build your Forest Admin app?
Webpack is mainly used to bundle frontend app, and forest-cli provides backend code that usually don’t need a build step to work.
Webpack can indeed be used to build NodeJS code, however, we’ve never tried to do so on our end.
I can’t think of specific reason that it wouldn’t work though.
In order to help, can you give me your Webpack config please? 