diff --git a/.gitignore b/.gitignore
index 672e243f1e..ee9a495df4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,8 @@ doc/
 test-npm-packages-app/
 .vscode/
 .DS_Store
-
-
 credentials.js
+*.d.ts
+*.js
+*.js.map
+tsconfig-build.tsbuildinfo
diff --git a/.mocharc.json b/.mocharc.json
new file mode 100644
index 0000000000..3e3e61dfd5
--- /dev/null
+++ b/.mocharc.json
@@ -0,0 +1,5 @@
+{
+    "diff": true,
+    "spec": ["./test/**/*.js", "./@here/*/test/**/*.js"],
+    "exclude": ["./@here/harp-mapview/test/resources/testWorker.js"]
+}
diff --git a/@here/harp-datasource-protocol/test/tsconfig-build.json b/@here/harp-datasource-protocol/test/tsconfig-build.json
new file mode 100644
index 0000000000..95222289ae
--- /dev/null
+++ b/@here/harp-datasource-protocol/test/tsconfig-build.json
@@ -0,0 +1,12 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-geoutils/tsconfig-build.json" },
+        { "path": "../../harp-utils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-datasource-protocol/tsconfig-build.json b/@here/harp-datasource-protocol/tsconfig-build.json
new file mode 100644
index 0000000000..009550a887
--- /dev/null
+++ b/@here/harp-datasource-protocol/tsconfig-build.json
@@ -0,0 +1,12 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-debug-datasource/tsconfig-build.json b/@here/harp-debug-datasource/tsconfig-build.json
new file mode 100644
index 0000000000..3c14e2a404
--- /dev/null
+++ b/@here/harp-debug-datasource/tsconfig-build.json
@@ -0,0 +1,13 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-lrucache/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-examples/package.json b/@here/harp-examples/package.json
index aa39659ed5..f5ae8ba18e 100644
--- a/@here/harp-examples/package.json
+++ b/@here/harp-examples/package.json
@@ -54,10 +54,11 @@
         "highlight.js": "^9.15.8",
         "html-webpack-plugin": "^3.2.0",
         "ncp": "^2.0.0",
+        "source-map-loader": "^0.2.4",
         "stats.js": "^0.17.0",
         "style-loader": "^0.23.0",
         "three": "^0.108.0",
-        "ts-loader": "^6.0.3",
+        "ts-loader": "^6.2.0",
         "typescript": "^3.6.3",
         "webpack": "^4.34.0",
         "webpack-cli": "^3.3.4",
diff --git a/@here/harp-examples/tsconfig-build.json b/@here/harp-examples/tsconfig-build.json
new file mode 100644
index 0000000000..5e8c2aa44e
--- /dev/null
+++ b/@here/harp-examples/tsconfig-build.json
@@ -0,0 +1,31 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": ".",
+        "resolveJsonModule": true
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-debug-datasource/tsconfig-build.json" },
+        { "path": "../harp-features-datasource/tsconfig-build.json" },
+        { "path": "../harp-geojson-datasource/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-map-controls/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-omv-datasource/tsconfig-build.json" },
+        { "path": "../harp-text-canvas/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" },
+        { "path": "../harp-webtile-datasource/tsconfig-build.json" }
+    ],
+    "include": [
+        "./*.ts",
+        "./src/*.ts",
+        "./lib/*.ts",
+        "./resources/*.ts",
+        "./decoder/*.ts",
+        "./src/*.tsx",
+        "./resources/**/*.json"
+    ],
+    "exclude": ["test/**/*.ts", "dist/**/*.ts"]
+}
diff --git a/@here/harp-examples/webpack-build.config.js b/@here/harp-examples/webpack-build.config.js
new file mode 100644
index 0000000000..3c4899e892
--- /dev/null
+++ b/@here/harp-examples/webpack-build.config.js
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2017-2018 HERE Europe B.V.
+ * Licensed under Apache 2.0, see full license in LICENSE
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * This basically downgrades original webpack.config.js to compile
+ * only JS created by `tsc -b .` (in current folder).
+ *
+ * This is much faster in bigger build process as Typescript runs only once.
+ *
+ * Usage:
+
+ * - Development
+
+ *    tsc --build tsconfig-build.json --watch --verbose --listEmittedFiles
+ *    webpack-dev-server --config webpack-build.config.js
+ *
+ * - CI
+ *    tsc --build tsconfig-build.json
+ *    webpack --config webpack-build.config.js
+ */
+const configs = require('./webpack.config');
+
+module.exports = configs.map(config => {
+    config.resolve.extensions = [".webpack.js", ".web.js", ".js"]
+    config.module.rules = config.module.rules.filter(rule => rule.loader !== "ts-loader")
+    config.module.rules.push({
+        rules: [
+            {
+                test: /\.js$/,
+                use: ["source-map-loader"],
+                enforce: "pre"
+            }
+        ]
+    })
+    for(const entry in config.entries) {
+        config.entries[entry] = config.entries[entry].replace(/.ts$/, ".js");
+    }
+    return config;
+})
+
+throw new Foo();
diff --git a/@here/harp-examples/webpack.config.js b/@here/harp-examples/webpack.config.js
index 43af74a2b8..f486c2a308 100644
--- a/@here/harp-examples/webpack.config.js
+++ b/@here/harp-examples/webpack.config.js
@@ -40,10 +40,7 @@ const commonConfig = {
         }
     ],
     resolve: {
-        extensions: [".webpack.js", ".web.ts", ".ts", ".tsx", ".web.js", ".js"],
-        alias: {
-            "react-native": "react-native-web"
-        }
+        extensions: [".webpack.js", ".web.ts", ".ts", ".tsx", ".web.js", ".js"]
     },
     module: {
         rules: [
diff --git a/@here/harp-features-datasource/tsconfig-build.json b/@here/harp-features-datasource/tsconfig-build.json
new file mode 100644
index 0000000000..0a25d6f285
--- /dev/null
+++ b/@here/harp-features-datasource/tsconfig-build.json
@@ -0,0 +1,14 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-geojson-datasource/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-omv-datasource/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-fetch/test/tsconfig-build.json b/@here/harp-fetch/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-fetch/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-fetch/tsconfig-build.json b/@here/harp-fetch/tsconfig-build.json
new file mode 100644
index 0000000000..f7f16c27c8
--- /dev/null
+++ b/@here/harp-fetch/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-geojson-datasource/tsconfig-build.json b/@here/harp-geojson-datasource/tsconfig-build.json
new file mode 100644
index 0000000000..b71fd5448f
--- /dev/null
+++ b/@here/harp-geojson-datasource/tsconfig-build.json
@@ -0,0 +1,18 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-fetch/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-lines/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-mapview-decoder/tsconfig-build.json" },
+        { "path": "../harp-transfer-manager/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-geometry/test/tsconfig-build.json b/@here/harp-geometry/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-geometry/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-geometry/tsconfig-build.json b/@here/harp-geometry/tsconfig-build.json
new file mode 100644
index 0000000000..71a229f1f6
--- /dev/null
+++ b/@here/harp-geometry/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../harp-geoutils/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-geoutils/test/tsconfig-build.json b/@here/harp-geoutils/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-geoutils/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-geoutils/tsconfig-build.json b/@here/harp-geoutils/tsconfig-build.json
new file mode 100644
index 0000000000..9ed9f86add
--- /dev/null
+++ b/@here/harp-geoutils/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "include": ["lib/**/*.ts", "index.ts"]
+}
diff --git a/@here/harp-lines/test/tsconfig-build.json b/@here/harp-lines/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-lines/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-lines/tsconfig-build.json b/@here/harp-lines/tsconfig-build.json
new file mode 100644
index 0000000000..d46906ed52
--- /dev/null
+++ b/@here/harp-lines/tsconfig-build.json
@@ -0,0 +1,12 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [
+        { "path": "../harp-utils/tsconfig-build.json" },
+        { "path": "../harp-materials/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-lrucache/test/tsconfig-build.json b/@here/harp-lrucache/test/tsconfig-build.json
new file mode 100644
index 0000000000..6d69f03e94
--- /dev/null
+++ b/@here/harp-lrucache/test/tsconfig-build.json
@@ -0,0 +1,11 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-utils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-lrucache/tsconfig-build.json b/@here/harp-lrucache/tsconfig-build.json
new file mode 100644
index 0000000000..537e77a94e
--- /dev/null
+++ b/@here/harp-lrucache/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [{ "path": "../harp-utils/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-map-controls/test/tsconfig-build.json b/@here/harp-map-controls/test/tsconfig-build.json
new file mode 100644
index 0000000000..a29db8b81b
--- /dev/null
+++ b/@here/harp-map-controls/test/tsconfig-build.json
@@ -0,0 +1,11 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-geoutils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-map-controls/tsconfig-build.json b/@here/harp-map-controls/tsconfig-build.json
new file mode 100644
index 0000000000..b32c066b97
--- /dev/null
+++ b/@here/harp-map-controls/tsconfig-build.json
@@ -0,0 +1,13 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-mapview-decoder/test/tsconfig-build.json b/@here/harp-mapview-decoder/test/tsconfig-build.json
new file mode 100644
index 0000000000..f9716329dd
--- /dev/null
+++ b/@here/harp-mapview-decoder/test/tsconfig-build.json
@@ -0,0 +1,11 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-test-utils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-mapview-decoder/tsconfig-build.json b/@here/harp-mapview-decoder/tsconfig-build.json
new file mode 100644
index 0000000000..8729c0af1d
--- /dev/null
+++ b/@here/harp-mapview-decoder/tsconfig-build.json
@@ -0,0 +1,16 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-fetch/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" },
+        { "path": "../harp-test-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-mapview/test/tsconfig-build.json b/@here/harp-mapview/test/tsconfig-build.json
new file mode 100644
index 0000000000..f9716329dd
--- /dev/null
+++ b/@here/harp-mapview/test/tsconfig-build.json
@@ -0,0 +1,11 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-test-utils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-mapview/tsconfig-build.json b/@here/harp-mapview/tsconfig-build.json
new file mode 100644
index 0000000000..bbd4121ecc
--- /dev/null
+++ b/@here/harp-mapview/tsconfig-build.json
@@ -0,0 +1,18 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-fetch/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-lines/tsconfig-build.json" },
+        { "path": "../harp-lrucache/tsconfig-build.json" },
+        { "path": "../harp-materials/tsconfig-build.json" },
+        { "path": "../harp-text-canvas/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-materials/lib/MapMeshMaterials.ts b/@here/harp-materials/lib/MapMeshMaterials.ts
index 364f535997..3ec303c7f9 100644
--- a/@here/harp-materials/lib/MapMeshMaterials.ts
+++ b/@here/harp-materials/lib/MapMeshMaterials.ts
@@ -689,7 +689,8 @@ export namespace ExtrusionFeature {
  *
  * @see [[Tile#addRenderHelper]]
  */
-export class ExtrusionFeatureMixin implements ExtrusionFeature {
+
+class ExtrusionFeatureMixin implements ExtrusionFeature {
     needsUpdate?: boolean;
     uniformsNeedUpdate?: boolean;
     private m_extrusion: number = ExtrusionFeature.DEFAULT_RATIO_MAX;
diff --git a/@here/harp-materials/tsconfig-build.json b/@here/harp-materials/tsconfig-build.json
new file mode 100644
index 0000000000..537e77a94e
--- /dev/null
+++ b/@here/harp-materials/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [{ "path": "../harp-utils/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-omv-datasource/test/tsconfig-build.json b/@here/harp-omv-datasource/test/tsconfig-build.json
new file mode 100644
index 0000000000..469bfcb270
--- /dev/null
+++ b/@here/harp-omv-datasource/test/tsconfig-build.json
@@ -0,0 +1,12 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-geoutils/tsconfig-build.json" },
+        { "path": "../../harp-mapview-decoder/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-omv-datasource/tsconfig-build.json b/@here/harp-omv-datasource/tsconfig-build.json
new file mode 100644
index 0000000000..f5a8122657
--- /dev/null
+++ b/@here/harp-omv-datasource/tsconfig-build.json
@@ -0,0 +1,20 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-fetch/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-lines/tsconfig-build.json" },
+        { "path": "../harp-lrucache/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-mapview-decoder/tsconfig-build.json" },
+        { "path": "../harp-transfer-manager/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" },
+        { "path": "../harp-geometry/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-test-utils/test/tsconfig-build.json b/@here/harp-test-utils/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-test-utils/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-test-utils/tsconfig-build.json b/@here/harp-test-utils/tsconfig-build.json
new file mode 100644
index 0000000000..537e77a94e
--- /dev/null
+++ b/@here/harp-test-utils/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [{ "path": "../harp-utils/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-text-canvas/test/tsconfig-build.json b/@here/harp-text-canvas/test/tsconfig-build.json
new file mode 100644
index 0000000000..f9716329dd
--- /dev/null
+++ b/@here/harp-text-canvas/test/tsconfig-build.json
@@ -0,0 +1,11 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [
+        { "path": "../tsconfig-build.json" },
+        { "path": "../../harp-test-utils/tsconfig-build.json" }
+    ]
+}
diff --git a/@here/harp-text-canvas/tsconfig-build.json b/@here/harp-text-canvas/tsconfig-build.json
new file mode 100644
index 0000000000..654e2010c5
--- /dev/null
+++ b/@here/harp-text-canvas/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../harp-lrucache/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-transfer-manager/test/tsconfig-build.json b/@here/harp-transfer-manager/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-transfer-manager/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-transfer-manager/tsconfig-build.json b/@here/harp-transfer-manager/tsconfig-build.json
new file mode 100644
index 0000000000..f5bbc9217d
--- /dev/null
+++ b/@here/harp-transfer-manager/tsconfig-build.json
@@ -0,0 +1,9 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../harp-fetch/tsconfig-build.json" }],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-utils/test/tsconfig-build.json b/@here/harp-utils/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-utils/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-utils/tsconfig-build.json b/@here/harp-utils/tsconfig-build.json
new file mode 100644
index 0000000000..204802c5ce
--- /dev/null
+++ b/@here/harp-utils/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp-webtile-datasource/test/tsconfig-build.json b/@here/harp-webtile-datasource/test/tsconfig-build.json
new file mode 100644
index 0000000000..88e7c082d7
--- /dev/null
+++ b/@here/harp-webtile-datasource/test/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "extends": "../../../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    },
+    "references": [{ "path": "../tsconfig-build.json" }]
+}
diff --git a/@here/harp-webtile-datasource/tsconfig-build.json b/@here/harp-webtile-datasource/tsconfig-build.json
new file mode 100644
index 0000000000..bd81ffd998
--- /dev/null
+++ b/@here/harp-webtile-datasource/tsconfig-build.json
@@ -0,0 +1,13 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp.gl/package.json b/@here/harp.gl/package.json
index 2519db1e6d..6a58902346 100644
--- a/@here/harp.gl/package.json
+++ b/@here/harp.gl/package.json
@@ -46,7 +46,7 @@
         "@here/harp-text-canvas": "^0.10.0",
         "@here/harp-utils": "^0.10.0",
         "@here/harp-webtile-datasource": "^0.10.0",
-        "ts-loader": "^6.0.3",
+        "ts-loader": "^6.2.0",
         "typescript": "^3.6.3",
         "webpack": "^4.34.0",
         "webpack-cli": "^3.3.4",
diff --git a/@here/harp.gl/tsconfig-build.json b/@here/harp.gl/tsconfig-build.json
new file mode 100644
index 0000000000..2c607dd1bb
--- /dev/null
+++ b/@here/harp.gl/tsconfig-build.json
@@ -0,0 +1,20 @@
+{
+    "extends": "../../tsconfig.settings.json",
+    "compilerOptions": {
+        "outDir": ".",
+        "rootDir": "."
+    },
+    "references": [
+        { "path": "../harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "../harp-features-datasource/tsconfig-build.json" },
+        { "path": "../harp-geojson-datasource/tsconfig-build.json" },
+        { "path": "../harp-geoutils/tsconfig-build.json" },
+        { "path": "../harp-map-controls/tsconfig-build.json" },
+        { "path": "../harp-mapview/tsconfig-build.json" },
+        { "path": "../harp-mapview-decoder/tsconfig-build.json" },
+        { "path": "../harp-omv-datasource/tsconfig-build.json" },
+        { "path": "../harp-utils/tsconfig-build.json" },
+        { "path": "../harp-webtile-datasource/tsconfig-build.json" }
+    ],
+    "exclude": ["test/**/*.ts"]
+}
diff --git a/@here/harp.gl/webpack.config.js b/@here/harp.gl/webpack.config.js
index b446f03467..07045a7002 100644
--- a/@here/harp.gl/webpack.config.js
+++ b/@here/harp.gl/webpack.config.js
@@ -11,31 +11,11 @@ const bundleSuffix = isProduction ? ".min" : "";
 const commonConfig = {
     devtool: "source-map",
     resolve: {
-        extensions: [".webpack.js", ".web.ts", ".ts", ".tsx", ".web.js", ".js"]
+        extensions: [".webpack.js", ".web.js", ".js"]
     },
     output: {
         path: path.join(process.cwd(), "dist")
     },
-    module: {
-        rules: [
-            {
-                test: /\.tsx?$/,
-                loader: "ts-loader",
-                exclude: /node_modules/,
-                options: {
-                    onlyCompileBundledFiles: true,
-                    // use the main tsconfig.json for all compilation
-                    // configFile: path.join(process.cwd(), "tsconfig.json"),
-                    configFile: fs.existsSync("../../tsconfig.json")
-                        ? path.resolve(__dirname, "../../tsconfig.json")
-                        : path.resolve(__dirname, "./tsconfig.json"),
-                    compilerOptions: {
-                        declaration: false
-                    }
-                }
-            }
-        ]
-    },
     plugins: [
         new webpack.EnvironmentPlugin({
             // default NODE_ENV to development. Override by setting the environment variable NODE_ENV to 'production'
@@ -50,7 +30,7 @@ const commonConfig = {
 };
 
 const mapComponentConfig = merge(commonConfig, {
-    entry: path.resolve(__dirname, "./lib/index.ts"),
+    entry: path.resolve(__dirname, "./lib/index.js"),
     output: {
         filename: `harp${bundleSuffix}.js`,
         library: "harp"
@@ -66,7 +46,7 @@ const mapComponentConfig = merge(commonConfig, {
 });
 
 const mapComponentDecoderConfig = merge(commonConfig, {
-    entry: path.resolve(__dirname, "./lib/DecoderBootstrap.ts"),
+    entry: path.resolve(__dirname, "./lib/DecoderBootstrap.js"),
     output: {
         filename: `harp-decoders${bundleSuffix}.js`
     },
diff --git a/package.json b/package.json
index 84ecd2e478..b28f04e5fa 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,7 @@
         "cov-test": "nyc mocha -r ts-node/register ./@here/*/test/*.ts",
         "cov-report-html": "nyc report --reporter=html",
         "start": "ts-node ./scripts/credentials.ts -- . && webpack-dev-server -d --config @here/harp-examples/webpack.config.js",
-        "build": "npm run build-bundle && npm run build-examples",
+        "build": "yarn build-bundle && yarn build-examples",
         "build-examples": "ts-node ./scripts/credentials.ts -- dist/examples && webpack -d --config @here/harp-examples/webpack.config.js",
         "build-bundle": "cd @here/harp.gl && webpack",
         "start-tests": "webpack-dev-server -d --config webpack.tests.config.js",
@@ -52,7 +52,11 @@
         "tslint:fix": "tslint --fix --project tsconfig.json",
         "prettier": "prettier -l \"**/*.ts\" \"**/*.tsx\" \"**/*.json\"",
         "prettier:fix": "prettier --write \"**/*.ts\" \"**/*.tsx\" \"**/*.json\"",
-        "postinstall": "ts-node ./scripts/postinstall.ts"
+        "postinstall": "ts-node ./scripts/postinstall.ts",
+        "tsc": "tsc -b ./tsconfig-build.json",
+        "tsc-examples": "tsc -b ./@here/harp-examples/tsconfig-build.json",
+        "tsc-sdk": "tsc -b ./tsconfig-build-sdk.json",
+        "tsc-tests": "tsc -b ./tsconfig-build-tests.json"
     },
     "engines": {
         "node": ">=10.5.0",
diff --git a/test/tsconfig-build.json b/test/tsconfig-build.json
new file mode 100644
index 0000000000..18b5b6cba9
--- /dev/null
+++ b/test/tsconfig-build.json
@@ -0,0 +1,7 @@
+{
+    "extends": "../tsconfig.settings.json",
+    "compilerOptions": {
+        "rootDir": ".",
+        "outDir": "."
+    }
+}
diff --git a/tsconfig-build-sdk.json b/tsconfig-build-sdk.json
new file mode 100644
index 0000000000..225b0ffed5
--- /dev/null
+++ b/tsconfig-build-sdk.json
@@ -0,0 +1,28 @@
+{
+    "files": [],
+    "compilerOptions": {
+        "composite": true
+    },
+    "references": [
+        { "path": "@here/harp.gl/tsconfig-build.json" },
+        { "path": "@here/harp-datasource-protocol/tsconfig-build.json" },
+        { "path": "@here/harp-fetch/tsconfig-build.json" },
+        { "path": "@here/harp-debug-datasource/tsconfig-build.json" },
+        { "path": "@here/harp-features-datasource/tsconfig-build.json" },
+        { "path": "@here/harp-geojson-datasource/tsconfig-build.json" },
+        { "path": "@here/harp-geometry/tsconfig-build.json" },
+        { "path": "@here/harp-geoutils/tsconfig-build.json" },
+        { "path": "@here/harp-lines/tsconfig-build.json" },
+        { "path": "@here/harp-lrucache/tsconfig-build.json" },
+        { "path": "@here/harp-map-controls/tsconfig-build.json" },
+        { "path": "@here/harp-mapview/tsconfig-build.json" },
+        { "path": "@here/harp-mapview-decoder/tsconfig-build.json" },
+        { "path": "@here/harp-materials/tsconfig-build.json" },
+        { "path": "@here/harp-omv-datasource/tsconfig-build.json" },
+        { "path": "@here/harp-utils/tsconfig-build.json" },
+        { "path": "@here/harp-test-utils/tsconfig-build.json" },
+        { "path": "@here/harp-text-canvas/tsconfig-build.json" },
+        { "path": "@here/harp-transfer-manager" },
+        { "path": "@here/harp-webtile-datasource/tsconfig-build.json" }
+    ]
+}
diff --git a/tsconfig-build-tests.json b/tsconfig-build-tests.json
new file mode 100644
index 0000000000..43a6063ee7
--- /dev/null
+++ b/tsconfig-build-tests.json
@@ -0,0 +1,24 @@
+{
+    "files": [],
+    "compilerOptions": {
+        "composite": true
+    },
+    "references": [
+        { "path": "test/tsconfig-build.json" },
+        { "path": "@here/harp-datasource-protocol/test/tsconfig-build.json" },
+        { "path": "@here/harp-fetch/test/tsconfig-build.json" },
+        { "path": "@here/harp-geoutils/test/tsconfig-build.json" },
+        { "path": "@here/harp-geometry/test/tsconfig-build.json" },
+        { "path": "@here/harp-lines/test/tsconfig-build.json" },
+        { "path": "@here/harp-lrucache/test/tsconfig-build.json" },
+        { "path": "@here/harp-map-controls/test/tsconfig-build.json" },
+        { "path": "@here/harp-mapview/test/tsconfig-build.json" },
+        { "path": "@here/harp-mapview-decoder/test/tsconfig-build.json" },
+        { "path": "@here/harp-omv-datasource/test/tsconfig-build.json" },
+        { "path": "@here/harp-utils/test/tsconfig-build.json" },
+        { "path": "@here/harp-test-utils/test/tsconfig-build.json" },
+        { "path": "@here/harp-text-canvas/test/tsconfig-build.json" },
+        { "path": "@here/harp-transfer-manager/test/tsconfig-build.json" },
+        { "path": "@here/harp-webtile-datasource/test/tsconfig-build.json" }
+    ]
+}
diff --git a/tsconfig-build.json b/tsconfig-build.json
new file mode 100644
index 0000000000..0c3b932cbc
--- /dev/null
+++ b/tsconfig-build.json
@@ -0,0 +1,8 @@
+{
+    "files": [],
+    "references": [
+        { "path": "./tsconfig-build-sdk.json" },
+        { "path": "./@here/harp-examples/tsconfig-build.json" },
+        { "path": "./tsconfig-build-tests.json" }
+    ]
+}
diff --git a/tsconfig.settings.json b/tsconfig.settings.json
new file mode 100644
index 0000000000..6ea21753d4
--- /dev/null
+++ b/tsconfig.settings.json
@@ -0,0 +1,18 @@
+{
+    "compilerOptions": {
+        "target": "es6",
+        "lib": ["es2017", "dom"],
+        "module": "commonjs",
+        "moduleResolution": "node",
+        "sourceMap": true,
+        "declaration": true,
+        "strictNullChecks": true,
+        "noImplicitAny": true,
+        "noImplicitReturns": true,
+        "noImplicitThis": true,
+        "noUnusedLocals": false,
+        "downlevelIteration": true,
+        "composite": true
+    },
+    "exclude": ["*.d.ts"]
+}
diff --git a/webpack.tests.config.js b/webpack.tests.config.js
index 8b53844be9..a22232cd18 100644
--- a/webpack.tests.config.js
+++ b/webpack.tests.config.js
@@ -21,26 +21,12 @@ const harpFontResourcesPath = path.dirname(require.resolve("@here/harp-fontcatal
 const browserTestsConfig = {
     devtool: "source-map",
     resolve: {
-        extensions: [".webpack.js", ".web.ts", ".ts", ".tsx", ".web.js", ".js"],
+        extensions: [".web.js", ".js"],
         modules: [".", "node_modules"]
     },
-    module: {
-        rules: [
-            {
-                test: /\.tsx?$/,
-                loader: "ts-loader",
-                exclude: /node_modules/,
-                options: {
-                    onlyCompileBundledFiles: true,
-                    // use the main tsconfig.json for all compilation
-                    configFile: path.resolve(__dirname, "tsconfig.json")
-                }
-            }
-        ]
-    },
     entry: {
-        test: glob.sync("@here/*/test/**/*.ts"),
-        "performance-test": glob.sync("test/performance/**/*.ts")
+        test: glob.sync("@here/*/test/**/*.js").filter(path => !path.includes("generator-harp.gl")),
+        "performance-test": glob.sync("test/performance/**/*.js")
     },
     output: {
         path: path.join(__dirname, "dist/test"),
@@ -94,6 +80,10 @@ const browserTestsConfig = {
         entrypoints: true,
         warnings: true
     },
+    watchOptions: {
+        aggregateTimeout: 300,
+        poll: 1000
+    },
     mode: process.env.NODE_ENV || "development"
 };
 
diff --git a/yarn.lock b/yarn.lock
index 1ae164159c..0199c8e005 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1041,7 +1041,7 @@ async@^1.5.2:
   resolved "https://registry.yarnpkg.com/async/-/async-1.5.2.tgz#ec6a61ae56480c0c3cb241c95618e20892f9672a"
   integrity sha1-7GphrlZIDAw8skHJVhjiCJL5Zyo=
 
-async@^2.6.0, async@^2.6.2:
+async@^2.5.0, async@^2.6.0, async@^2.6.2:
   version "2.6.3"
   resolved "https://registry.yarnpkg.com/async/-/async-2.6.3.tgz#d72625e2344a3656e3a3ad4fa749fa83299d82ff"
   integrity sha512-zflvls11DCy+dQWzTW2dzuilv8Z5X/pjfmZOWba6TNIVDm+2UDaJmXSOXlasHKfNBs8oo3M0aT50fDEWfKZjXg==
@@ -7219,6 +7219,14 @@ source-list-map@^2.0.0:
   resolved "https://registry.yarnpkg.com/source-list-map/-/source-list-map-2.0.1.tgz#3993bd873bfc48479cca9ea3a547835c7c154b34"
   integrity sha512-qnQ7gVMxGNxsiL4lEuJwe/To8UnK7fAnmbGEEH8RpLouuKbeEm0lhbQVFIrNSuB+G7tVrAlVsZgETT5nljf+Iw==
 
+source-map-loader@^0.2.4:
+  version "0.2.4"
+  resolved "https://registry.yarnpkg.com/source-map-loader/-/source-map-loader-0.2.4.tgz#c18b0dc6e23bf66f6792437557c569a11e072271"
+  integrity sha512-OU6UJUty+i2JDpTItnizPrlpOIBLmQbWMuBg9q5bVtnHACqw1tn9nNwqJLbv0/00JjnJb/Ee5g5WS5vrRv7zIQ==
+  dependencies:
+    async "^2.5.0"
+    loader-utils "^1.1.0"
+
 source-map-resolve@^0.5.0:
   version "0.5.2"
   resolved "https://registry.yarnpkg.com/source-map-resolve/-/source-map-resolve-0.5.2.tgz#72e2cc34095543e43b2c62b2c4c10d4a9054f259"
@@ -7886,10 +7894,10 @@ ts-json-schema-generator@^0.47.0:
     json-stable-stringify "^1.0.1"
     typescript "~3.5.2"
 
-ts-loader@^6.0.3:
-  version "6.1.0"
-  resolved "https://registry.yarnpkg.com/ts-loader/-/ts-loader-6.1.0.tgz#999cb0a7644f9c7c6c0901802dce50ceb0a76e5b"
-  integrity sha512-7JedeOu2rsYHQDEr2fwmMozABwbQTZXEaEMZPSIWG7gpzRefOLJCqwdazcegHtyaxp04PeEgs/b0m08WMpnIzQ==
+ts-loader@^6.2.0:
+  version "6.2.0"
+  resolved "https://registry.yarnpkg.com/ts-loader/-/ts-loader-6.2.0.tgz#52d3993ecbc5474c1513242388e1049da0fce880"
+  integrity sha512-Da8h3fD+HiZ9GvZJydqzk3mTC9nuOKYlJcpuk+Zv6Y1DPaMvBL+56GRzZFypx2cWrZFMsQr869+Ua2slGoLxvQ==
   dependencies:
     chalk "^2.3.0"
     enhanced-resolve "^4.0.0"