On the Symfony blog they've released an announcement about the release of a tool that wants to help make it easier for Symfony developers to work with frontend resources using the Webpack standard: Webpack Encore.
For everyone that has hit [the barrier of complexity in frontend dependencies and compilation], I'm very excited to show you something we've been working on for the last few months: Webpack Encore.Encore gives you powerful CSS and JavaScript processing, combination, minification and a lot more, wrapped up in a simple API that's built on an industry-standard tool (Webpack).
He includes an example of the Javascript configuration to build out the Javascript, CSS and dependencies required for his build. He talks briefly about the conformity to the Webpack handling and how Encore fills that role in Symfony applications. The post ends linking to the project repository and the changes required to get the package installed.