I am working on a React application and uses Webpack to create bundle.js file. Even though my application is very simple bundle.js file size is around 11MB. 

When I analyze the bundle file with <https://webpack.github.io/analyse/>, more than 1000 packages are included in the bundle.js. Some of those packages are defined in devDependencies section of the package.json file. 

Therefore I am looking for answers to following questions.
Is there a way to reduce file size of the webpack compilation?
Does webpack include devDependencies modules in final bundle.js?