I have issue when I set "optimization": true on "qa" and "produciton" environemnts. When application is builded my markups is broken as it doesnt see styles.scss file at all. I can see it in browser source tab and all my classes inside but for some reason they are not applied when "optimization": true "optimization": false, removes an issue but I wanted to know why true affects on that. here is my angular.json { "$schema": "./node_modules/@angular/cli/lib/config/schema.json", "version": 1, "newProjectRoot": "projects", "projects": { "my-app": { "projectType": "application", "schematics": { "@schematics/angular:component": { "style": "scss" } }, "root": "", "sourceRoot": "src", "prefix": "app", "architect": { "build": { "builder": "@angular-devkit/build-angular:application", "options": { "outputPath": { "base": "dist", "browser": "" }, "index": "src/index.html", "browser": "src/main.ts", "polyfills": ["zone.js"], "tsConfig": "tsconfig.app.json", "inlineStyleLanguage": "scss", "stylePreprocessorOptions": { "includePaths": ["src/styles/lib", "src/styles/core/env", "src/styles"] }, "assets": ["src/favicon.ico", "src/assets", "src/web.config"], "styles": [ "src/styles/styles.scss", "@angular/material/prebuilt-themes/indigo-pink.css" ], "scripts": [], "allowedCommonJsDependencies": [ "highcharts/highcharts-more", "highcharts/highstock", "highcharts/modules/data", "highcharts/modules/exporting", "highcharts/modules/windbarb" ] }, "configurations": { "qa": { "outputHashing": "bundles", "optimization": true, "sourceMap": false, "namedChunks": false, "extractLicenses": true, "fileReplacements": [ { "replace": "src/environments/environment.ts", "with": "src/environments/environment.qa.ts" } ] }, Continue reading...