diff --git a/gulpfile.js b/gulpfile.js
index 91d3a3ade..c27abefcb 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -50,14 +50,6 @@ gulp.task('build:backend:style', () => {
 		.pipe(gulp.dest('./packages/backend/built/server/web/'));
 });
 
-gulp.task('clean', cb =>
-	rimraf('./built', cb)
-);
-
-gulp.task('cleanall', gulp.parallel('clean', cb =>
-	rimraf('./node_modules', cb)
-));
-
 gulp.task('build', gulp.parallel(
 	'copy:client:locales', 'copy:backend:views', 'build:backend:script', 'build:backend:style', 'copy:client:fonts'
 ));
diff --git a/package.json b/package.json
index 66d52e578..129e0f111 100644
--- a/package.json
+++ b/package.json
@@ -8,22 +8,19 @@
 	},
 	"private": true,
 	"scripts": {
+		"postinstall": "node ./scripts/install-packages.js",
+		"build": "node ./scripts/build.js",
 		"start": "cd packages/backend && node --experimental-json-modules ./built/index.js",
 		"start:test": "cd packages/backend && cross-env NODE_ENV=test node --experimental-json-modules ./index.js",
 		"init": "npm run migrate",
 		"ormconfig": "node ./packages/backend/ormconfig.js",
 		"migrate": "cd packages/backend && npx typeorm migration:run",
 		"migrateandstart": "npm run migrate && npm run start",
-		"build": "npm run build-client && npm run build-backend && npm run build-gulp",
-		"build-client": "cd packages/client && npm run build",
-		"build-backend": "cd packages/backend && npm run build",
-		"build-gulp": "gulp build",
+		"gulp": "gulp build",
 		"watch": "concurrently \"npm:watch-*\"",
 		"watch-webpack": "webpack --watch",
 		"watch-ts": "tsc -w -p packages/tsconfig.json && tsc-alias -w -p packages/tsconfig.json",
 		"watch-gulp": "gulp watch",
-		"clean": "gulp clean",
-		"cleanall": "gulp cleanall",
 		"lint": "tslint 'packages/**/*.ts'",
 		"cy:open": "cypress open",
 		"cy:run": "cypress run",
@@ -35,6 +32,7 @@
 	"dependencies": {
 		"@types/gulp": "4.0.9",
 		"@types/gulp-rename": "2.0.1",
+		"execa": "5.1.1",
 		"gulp": "4.0.2",
 		"gulp-cssnano": "2.1.3",
 		"gulp-rename": "2.0.0",
diff --git a/scripts/build.js b/scripts/build.js
new file mode 100644
index 000000000..6d4bb6c6e
--- /dev/null
+++ b/scripts/build.js
@@ -0,0 +1,33 @@
+const execa = require('execa');
+
+(async () => {
+	console.log('building packages/backend ...');
+
+	await execa('npm', ['run', 'build'], {
+		cwd: __dirname + '/../packages/backend',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+
+	console.log('building packages/client ...');
+
+	await execa('npm', ['run', 'build'], {
+		cwd: __dirname + '/../packages/client',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+
+	await execa('npm', ['run', 'build'], {
+		cwd: __dirname + '/../packages/client',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+
+	console.log('build finishing ...');
+
+	await execa('npm', ['run', 'gulp'], {
+		cwd: __dirname + '/../',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+})();
diff --git a/scripts/install-packages.js b/scripts/install-packages.js
new file mode 100644
index 000000000..c25063b29
--- /dev/null
+++ b/scripts/install-packages.js
@@ -0,0 +1,19 @@
+const execa = require('execa');
+
+(async () => {
+	console.log('installing dependencies of packages/backend ...');
+
+	await execa('yarn', ['install'], {
+		cwd: __dirname + '/../packages/backend',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+
+	console.log('installing dependencies of packages/client ...');
+
+	await execa('yarn', ['install'], {
+		cwd: __dirname + '/../packages/client',
+		stdout: process.stdout,
+		stderr: process.stderr,
+	});
+})();