diff --git a/lib/framework.js b/lib/framework.js
index c1c9db8c..96331368 100644
--- a/lib/framework.js
+++ b/lib/framework.js
@@ -9,17 +9,16 @@ const httpProxy = require("http-proxy");
 const fs = require("fs");
 const path = require("path");
 const yaml = require("js-yaml");
+const {Router} = require("express");
 const stat = fs.statSync;
 const {ErrorMessage} = require("./errors");
 
 
 class Framework {
 	constructor() {
-		this.isPaused = true;
-		this.queue = [];
-		this._serveResources = null;
-		this._serveThemes = null;
 		this.config = {};
+		this.beforeMiddleware = new Router();
+		this.middleware = new Router();
 	}
 
 	createPluginFilesPattern(pattern) {
@@ -120,7 +119,6 @@ class Framework {
 		this.config.client.ui5 = {};
 		this.config.client.ui5.useIframe = true; // for now only allow using iframes in HTML mode
 		this.config.ui5 = config.ui5 || {};
-		this.config.proxies = config.proxies || {};
 		this.config.middleware = config.middleware || [];
 		this.config.files = config.files || [];
 		this.config.beforeMiddleware = config.beforeMiddleware || [];
@@ -263,7 +261,6 @@ class Framework {
 			this.config.files.push(
 				this.createProjectFilesPattern(config.basePath + `/{${webappFolder}/**,${webappFolder}/**/.*}`)
 			);
-			// No proxy required here, local files will be loaded via karma first
 		} else if (config.ui5.type === "library") {
 			const srcFolder = this.config.ui5.paths.src;
 			const testFolder = this.config.ui5.paths.test;
@@ -281,12 +278,6 @@ class Framework {
 				this.createProjectFilesPattern(`${config.basePath}/{${srcFolder}/**,${srcFolder}/**/.*}`),
 				this.createProjectFilesPattern(`${config.basePath}/{${testFolder}/**,${testFolder}/**/.*}`),
 			);
-			// Configure proxies to first load files from karma server (e.g. library under test)
-			// Otherwise the coverage reporting won't work
-			this.config.proxies[`/base/${this.replaceLast(srcFolder, "resources")}/`] = `/base/${srcFolder}/`;
-			this.config.proxies[`/base/${this.replaceLast(srcFolder, "test-resources")}/`] = `/base/${testFolder}/`;
-			this.config.proxies[`/base/${this.replaceLast(testFolder, "resources")}/`] = `/base/${srcFolder}/`;
-			this.config.proxies[`/base/${this.replaceLast(testFolder, "test-resources")}/`] = `/base/${testFolder}/`;
 		} else {
 			this.logger.log("error", ErrorMessage.invalidProjectType(config.ui5.type) );
 			throw new Error(ErrorMessage.failure());
@@ -370,6 +361,20 @@ class Framework {
 	// 	}
 	// }
 
+	/**
+	 * Rewrites the given url to use a virtual path that can be resolved
+	 * by the UI5 Tooling middleware or to conform with the UI5 CDN.
+	 *
+	 * Example (application):
+	 * /base/webapp/resources/sap-ui-core.js -> /resources/sap-ui-core.js
+	 *
+	 * Example (library):
+	 * /base/src/resources/sap-ui-core.js -> /resources/sap-ui-core.js
+	 * /base/test/test-resources/sap-ui-core.js -> /test-resources/sap-ui-core.js
+	 *
+	 * @param {string} url
+	 * @returns {string}
+	 */
 	rewriteUrl(url) {
 		const type = this.config.ui5.type;
 		const webappFolder = this.config.ui5.paths.webapp;
@@ -402,22 +407,50 @@ class Framework {
 		return url;
 	}
 
-	processRequests() {
-		this.isPaused = false;
-		this.queue.forEach(function(next) {
-			next();
-		});
-		this.queue = [];
-	}
-
-	pauseRequests() {
-		return (req, res, next) => {
-			if (this.isPaused) {
-				this.queue.push(next);
-			} else {
-				next();
-			}
-		};
+	/**
+	 * Rewrites the given url from a virtual path (resources / test-resources)
+	 * to a filesystem path so that the request can be handled by the karma
+	 * middleware that serves the project files.
+	 *
+	 * This is only relevant for type "library", as it has two separate folders (src / test).
+	 *
+	 * Example:
+	 * /base/resources/sap-ui-core.js -> /base/src/sap-ui-core.js
+	 * /base/test-resources/sap/ui/test/ -> /base/test/sap/ui/test/
+	 *
+	 * @param {string} url
+	 * @returns {string}
+	 */
+	rewriteUrlBefore(url) {
+		const type = this.config.ui5.type;
+		if (type !== "library") {
+			// Only rewrite "before" for type library
+			return url;
+		}
+		const srcFolder = this.config.ui5.paths.src;
+		const testFolder = this.config.ui5.paths.test;
+		const resourcesSrcPattern = new RegExp(
+			`/base/${this.replaceLast(srcFolder, "resources")}/`
+		);
+		const resourcesTestPattern = new RegExp(
+			`/base/${this.replaceLast(testFolder, "resources")}/`
+		);
+		const testResourcesSrcPattern = new RegExp(
+			`/base/${this.replaceLast(srcFolder, "test-resources")}/`
+		);
+		const testResourcesTestPattern = new RegExp(
+			`/base/${this.replaceLast(testFolder, "test-resources")}/`
+		);
+		if (resourcesSrcPattern.test(url)) {
+			return url.replace(resourcesSrcPattern, `/base/${srcFolder}/`);
+		} else if (resourcesTestPattern.test(url)) {
+			return url.replace(resourcesTestPattern, `/base/${srcFolder}/`);
+		} else if (testResourcesSrcPattern.test(url)) {
+			return url.replace(testResourcesSrcPattern, `/base/${testFolder}/`);
+		} else if (testResourcesTestPattern.test(url)) {
+			return url.replace(testResourcesTestPattern, `/base/${testFolder}/`);
+		}
+		return url;
 	}
 
 	async setupUI5Server({basePath, configPath}) {
@@ -447,8 +480,7 @@ class Framework {
 			all
 		};
 
-		// eslint-disable-next-line new-cap
-		const router = require("express").Router();
+		const router = new Router();
 
 		// TODO: rework ui5-server API and make public
 		const MiddlewareManager = require("@ui5/server/lib/middleware/MiddlewareManager");
@@ -459,9 +491,7 @@ class Framework {
 
 		await middlewareManager.applyMiddleware(router);
 
-		return {
-			serveResources: router
-		};
+		return router;
 	}
 
 	setupProxy({url}) {
@@ -474,50 +504,42 @@ class Framework {
 			agent
 		});
 
-		return {
-			serveResources: (req, res, next) => proxy.web(req, res, next),
-			serveThemes: undefined
-		};
+		return (req, res, next) => proxy.web(req, res, next);
+	}
+
+	beforeMiddlewareRewriteUrl(req, res, next) {
+		req.url = this.rewriteUrlBefore(req.url);
+		next();
+	}
+
+	middlewareRewriteUrl(req, res, next) {
+		req.url = this.rewriteUrl(req.url);
+		next();
 	}
 
 	async setupMiddleware() {
 		const config = this.config;
 
-		let server = {
-			serveResources: undefined,
-			serveThemes: undefined
-		};
+		if (config.ui5.type === "library") {
+			this.beforeMiddleware.use(this.beforeMiddlewareRewriteUrl.bind(this));
+			config.beforeMiddleware.push("ui5--beforeMiddleware");
+		}
 
+		let middleware;
 		if (config.ui5.url) {
-			config.middleware.push("ui5--serveResources");
-			server = await this.setupProxy(config.ui5);
+			middleware = this.setupProxy(config.ui5);
 		} else if (config.ui5.useMiddleware !== false) {
-			config.beforeMiddleware.push("ui5--pauseRequests");
-			config.middleware.push("ui5--serveResources");
-			// config.middleware.push("ui5--serveThemes");
-			server = await this.setupUI5Server({
+			middleware = await this.setupUI5Server({
 				basePath: config.basePath,
 				configPath: config.ui5.configPath
 			});
 		}
 
-		this._serveResources = server.serveResources;
-		this._serveThemes = server.serveThemes;
-		this.processRequests();
-		return this;
-	}
-
-	serveResources() {
-		return (req, res, next) => {
-			req.url = this.rewriteUrl(req.url);
-			this._serveResources(req, res, next);
-		};
-	}
-
-	serveThemes() {
-		return (req, res, next) => {
-			this._serveThemes(req, res, next);
-		};
+		if (middleware) {
+			this.middleware.use(this.middlewareRewriteUrl.bind(this));
+			this.middleware.use(middleware);
+			config.middleware.push("ui5--middleware");
+		}
 	}
 }
 
diff --git a/lib/index.js b/lib/index.js
index 2d829731..967f2e19 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,8 +7,7 @@ async function init(config, logger) {
 		await framework.init({config, logger});
 	} catch (error) {
 		const _logger = logger.create("ui5.framework");
-		_logger.log("error", error.message);
-		_logger.log("debug", error.stack);
+		_logger.log("error", error.stack);
 		throw new Error(ErrorMessage.failure());
 	}
 }
@@ -17,13 +16,6 @@ init.$inject = ["config", "logger"];
 
 module.exports = {
 	"framework:ui5": ["factory", init],
-	"middleware:ui5--pauseRequests": ["factory", function() {
-		return framework.pauseRequests();
-	}],
-	"middleware:ui5--serveResources": ["factory", function() {
-		return framework.serveResources();
-	}],
-	"middleware:ui5--serveThemes": ["factory", function() {
-		return framework.serveThemes();
-	}]
+	"middleware:ui5--beforeMiddleware": ["value", framework.beforeMiddleware],
+	"middleware:ui5--middleware": ["value", framework.middleware]
 };
diff --git a/test/unit/framework.test.js b/test/unit/framework.test.js
index 11cccc47..62df08e0 100644
--- a/test/unit/framework.test.js
+++ b/test/unit/framework.test.js
@@ -17,130 +17,78 @@ const logger = {
 };
 
 describe("Middleware for UI5", () => {
-	it("Should pause requests during UI5 server setup and resume once ready", async () => {
+	it("Should rewrite url in beforeMiddleware (library only)", async () => {
 		let resolve;
 		const donePromise = new Promise((_resolve) => {
 			resolve = _resolve;
 		});
-		expect.assertions(7);
+		expect.assertions(4);
 
 		const config = {
 			ui5: {
-				useMiddleware: true
+				type: "library"
 			}
 		};
 		const framework = new Framework();
 		framework.exists = () => true;
-		const initPromise = framework.init({config, logger});
-
-		expect(config["beforeMiddleware"]).toContain("ui5--pauseRequests");
-		expect(framework.isPaused).toBe(true);
+		await framework.init({config, logger});
+		expect(config["middleware"]).toContain("ui5--middleware");
+		expect(config["beforeMiddleware"]).toContain("ui5--beforeMiddleware");
 
-		const processRequestsSpy = jest.spyOn(framework, "processRequests");
+		const rewriteUrlBeforeSpy = jest.spyOn(framework, "rewriteUrlBefore");
 
-		const pauseRequestsMiddleware = framework.pauseRequests();
-		pauseRequestsMiddleware({}, {}, function() {
-			expect(processRequestsSpy).toBeCalled();
-			expect(framework.isPaused).toBe(false);
+		const beforeMiddleware = framework.beforeMiddleware;
 
-			setTimeout(function() {
-				// Queue should be empty after paused requests have been called
-				expect(framework.queue).toHaveLength(0);
+		const req = {
+			url: "/foo"
+		};
 
-				// New requests shouldn't be queued anymore
-				pauseRequestsMiddleware({}, {}, function() {
-					expect(framework.queue).toHaveLength(0);
-					resolve();
-				});
-			}, 0);
+		beforeMiddleware(req, {}, function() {
+			expect(rewriteUrlBeforeSpy).toBeCalledWith("/foo");
+			expect(req.url).toBe("/foo");
+			resolve();
 		});
-		expect(framework.queue).toHaveLength(1);
-
-		await initPromise;
 
 		return donePromise;
 	});
 
-	it("Should rewrite url in serveResources middleware", async () => {
+	it("Should rewrite url in middleware", async () => {
 		let resolve;
 		const donePromise = new Promise((_resolve) => {
 			resolve = _resolve;
 		});
-		expect.assertions(6);
+		expect.assertions(3);
 
 		const config = {
 			ui5: {
-				type: "application",
-				useMiddleware: true
+				type: "application"
 			}
 		};
 		const framework = new Framework();
 		framework.exists = () => true;
-		const initPromise = framework.init({config, logger});
-		expect(config["middleware"]).toContain("ui5--serveResources");
-		expect(framework.isPaused).toBe(true);
+		await framework.init({config, logger});
+		expect(config["middleware"]).toContain("ui5--middleware");
 
 		const rewriteUrlSpy = jest.spyOn(framework, "rewriteUrl");
 
-		const pauseRequestsMiddleware = framework.pauseRequests();
-		const serveResourcesMiddleware = framework.serveResources();
-
-		pauseRequestsMiddleware({}, {}, function() {
-			expect(framework.isPaused).toBe(false);
-			const internalServeResourcesSpy = jest.spyOn(framework, "_serveResources");
-
-			const req = {url: "/foo"};
-			const res = {};
-			const next = function() {
-				expect(internalServeResourcesSpy).toBeCalledWith(req, res, next);
-				expect(rewriteUrlSpy).toBeCalledWith("/foo");
-				expect(req.url).toBe("/foo");
-				resolve();
-			};
-			serveResourcesMiddleware(req, res, next);
-		});
-
-		await initPromise;
+		const middleware = framework.middleware;
 
-		return donePromise;
-	});
-
-	it.skip("Should not rewrite url in serveThemes middleware", async (done) => {
-		const config = {
-			ui5: {
-				useMiddleware: true
-			}
+		const req = {
+			url: "/foo"
 		};
-		const framework = new Framework();
-		framework.exists = () => true;
-		await framework.init({config, logger});
-		expect(config["middleware"]).toContain("ui5--serveThemes");
-		expect(framework.isPaused).toBe(true);
 
-		const rewriteUrlSpy = jest.spyOn(framework, "rewriteUrl");
-
-		const pauseRequestsMiddleware = framework.pauseRequests();
-		const serveThemesMiddleware = framework.serveThemes();
-
-		pauseRequestsMiddleware({}, {}, function() {
-			expect(framework.isPaused).toBe(false);
-			const internalServeThemesSpy = jest.spyOn(framework, "_serveThemes");
-
-			const req = {url: "/foo"};
-			const res = {};
-			const next = function() {
-				expect(internalServeThemesSpy).toBeCalledWith(req, res, next);
-				expect(rewriteUrlSpy).not.toBeCalled();
-				expect(req.url).toBe("/foo");
-				done();
-			};
-			serveThemesMiddleware(req, res, next);
+		middleware(req, {}, function() {
+			expect(rewriteUrlSpy).toBeCalledWith("/foo");
+			expect(req.url).toBe("/foo");
+			resolve();
 		});
+
+		return donePromise;
 	});
 });
 
 describe("Proxy for UI5 ", () => {
-	it("Should call proxy module from serveResources middleware (http)", (done) => {
+	it("Should call proxy module from middleware (http)", (done) => {
 		const proxyServer = new Framework().setupProxy({
 			url: "http://localhost"
 		});
@@ -159,18 +107,16 @@ describe("Proxy for UI5 ", () => {
 
 		// const proxy = require("http-proxy").createProxyServer.mock.results[0].value;
 
-		expect(proxyServer.serveThemes).toBeUndefined();
-
 		const req = {};
 		const res = {};
 		const next = function() {
 			// expect(proxy.web).toBeCalledWith(req, res, next); // TODO: check why this fails
 			done();
 		};
-		proxyServer.serveResources(req, res, next);
+		proxyServer(req, res, next);
 	});
 
-	it("Should call proxy module from serveResources middleware (https)", (done) => {
+	it("Should call proxy module from middleware (https)", (done) => {
 		const proxyServer = new Framework().setupProxy({
 			url: "https://localhost"
 		});
@@ -189,15 +135,13 @@ describe("Proxy for UI5 ", () => {
 
 		// const proxy = require("http-proxy").createProxyServer.mock.results[0].value;
 
-		expect(proxyServer.serveThemes).toBeUndefined();
-
 		const req = {};
 		const res = {};
 		const next = function() {
 			// expect(proxy.web).toBeCalledWith(req, res, next); // TODO: check why this fails
 			done();
 		};
-		proxyServer.serveResources(req, res, next);
+		proxyServer(req, res, next);
 	});
 });
 
@@ -387,7 +331,7 @@ describe("ui5.paths handling", () => {
 	});
 });
 
-describe("Utility functions", () => {
+describe("rewriteUrl", () => {
 	const framework = new Framework();
 	framework.exists = () => true;
 	framework.init({config: { }, logger});
@@ -531,6 +475,135 @@ describe("Utility functions", () => {
 	});
 });
 
+describe("rewriteUrlBefore", () => {
+	const framework = new Framework();
+	framework.exists = () => true;
+	framework.init({config: { }, logger});
+
+	const assertRewriteUrlBefore = ([input, expected]) => {
+		expect(framework.rewriteUrlBefore(input)).toEqual(expected);
+	};
+
+	it("Should rewrite url for library", async () => {
+		framework.config.ui5.type = "library";
+
+		// Good path
+		assertRewriteUrlBefore([
+			"/base/resources/sap-ui-core.js",
+			"/base/src/sap-ui-core.js",
+		]);
+		assertRewriteUrlBefore([
+			"/base/test-resources/sap/ui/test/",
+			"/base/test/sap/ui/test/"
+		]);
+
+		// Sad path (no rewrite)
+		assertRewriteUrlBefore([
+			"/base/src/sap-ui-core.js",
+			"/base/src/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/test/sap/ui/test/",
+			"/base/test/sap/ui/test/"
+		]);
+	});
+
+	it("Should rewrite url for library (nested paths)", async () => {
+		framework.config.ui5.type = "library";
+		framework.config.ui5.paths = {
+			src: "src/main/js",
+			test: "src/test/js"
+		};
+
+		// Good path
+		assertRewriteUrlBefore([
+			"/base/src/main/resources/sap-ui-core.js",
+			"/base/src/main/js/sap-ui-core.js",
+		]);
+		assertRewriteUrlBefore([
+			"/base/src/test/test-resources/sap/ui/test/",
+			"/base/src/test/js/sap/ui/test/"
+		]);
+
+		assertRewriteUrlBefore([
+			"/base/src/test/resources/sap-ui-core.js",
+			"/base/src/main/js/sap-ui-core.js",
+		]);
+		assertRewriteUrlBefore([
+			"/base/src/main/test-resources/sap/ui/test/",
+			"/base/src/test/js/sap/ui/test/"
+		]);
+
+		// Sad path (no rewrite)
+		assertRewriteUrlBefore([
+			"/base/src/main/js/sap-ui-core.js",
+			"/base/src/main/js/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/src/test/js/sap/ui/test/",
+			"/base/src/test/js/sap/ui/test/"
+		]);
+	});
+
+	it("Should not rewrite url for type application", async () => {
+		framework.config.ui5.type = "application";
+
+		assertRewriteUrlBefore([
+			"/base/webapp/resources/sap-ui-core.js",
+			"/base/webapp/resources/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/webapp/test-resources/sap/ui/test/",
+			"/base/webapp/test-resources/sap/ui/test/"
+		]);
+		assertRewriteUrlBefore([
+			"/base/webapp/foo.js",
+			"/base/webapp/foo.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/src/sap-ui-core.js",
+			"/base/src/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/test/sap/ui/test/",
+			"/base/test/sap/ui/test/"
+		]);
+		assertRewriteUrlBefore([
+			"/base/foo.js",
+			"/base/foo.js"
+		]);
+	});
+
+	it("Should not rewrite url when no type is given", async () => {
+		framework.config.ui5.type = undefined;
+
+		assertRewriteUrlBefore([
+			"/base/webapp/resources/sap-ui-core.js",
+			"/base/webapp/resources/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/webapp/test-resources/sap/ui/test/",
+			"/base/webapp/test-resources/sap/ui/test/"
+		]);
+		assertRewriteUrlBefore([
+			"/base/webapp/foo.js",
+			"/base/webapp/foo.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/src/sap-ui-core.js",
+			"/base/src/sap-ui-core.js"
+		]);
+		assertRewriteUrlBefore([
+			"/base/test/sap/ui/test/",
+			"/base/test/sap/ui/test/"
+		]);
+		assertRewriteUrlBefore([
+			"/base/foo.js",
+			"/base/foo.js"
+		]);
+	});
+});
+
 describe("Plugin setup", () => {
 	it("Should include browser bundle", async () => {
 		const config = {
@@ -619,9 +692,6 @@ describe("Types configuration", () => {
 		await framework.init({config, logger});
 		expect(config.files.find((file) => file.pattern.endsWith("/{src/**,src/**/.*}"))).toBeDefined();
 		expect(config.files.find((file) => file.pattern.endsWith("/{test/**,test/**/.*}"))).toBeDefined();
-
-		expect(config.proxies["/base/resources/"]).toEqual("/base/src/");
-		expect(config.proxies["/base/test-resources/"]).toEqual("/base/test/");
 	});
 
 	// TODO: What should happen?