tlaternet-templates/webpack.prod.js

const merge = require("webpack-merge");
const common = require("./webpack.common.js");
const UglifyJsPlugin = require("uglifyjs-webpack-plugin");
const OptimizeCSSAssetsPlugin = require("optimize-css-assets-webpack-plugin");

module.exports = merge(common, {
    optimization: {
        minimizer: [
            new UglifyJsPlugin({
                cache: true,
                parallel: true,
                sourceMap: true
            }),
            new OptimizeCSSAssetsPlugin({})
        ]
    },
    devtool: "source-map",
    mode: "production"
});