Add Azure Web Apps deployment guidance to README

Author: oegedijk

README.md

@@ -547,6 +547,68 @@ For platform-specific guides, see:
 [Deploying to Fly.io](https://explainerdashboard.readthedocs.io/en/latest/deployment.html#deploying-to-fly-io)
 and
 [Deploying to Hugging Face Spaces](https://explainerdashboard.readthedocs.io/en/latest/deployment.html#deploying-to-hugging-face-spaces).
+and
+[Deploying to Azure Web Apps](#deploying-to-azure-web-apps).
+
+### Deploying to Azure Web Apps
+
+If your app gets stuck on the dashboard `Loading...` screen on Azure, the most common
+issue is that the dashboard HTML is returned, but Dash endpoints such as
+`/_dash-layout`, `/_dash-dependencies`, or `/_dash-component-suites/*` are not mounted
+on the same Flask server and base path.
+
+Use a single WSGI app (`app = db.flask_server()`) and run it with `gunicorn`.
+Also avoid re-building the model/explainer inside a Flask request handler.
+
+**dashboard.py**:
+```python
+import os
+from explainerdashboard import ClassifierExplainer, ExplainerDashboard
+
+# Build/load these once at startup:
+# model = ...
+# X_test = ...
+# y_test = ...
+
+explainer = ClassifierExplainer(model, X_test, y_test)
+
+# If your app is mounted under a subpath, e.g. "/dashboard/",
+# set APP_BASE_PATH=/dashboard/ in Azure App Settings.
+base_path = os.getenv("APP_BASE_PATH", "/")
+if not base_path.startswith("/"):
+    base_path = "/" + base_path
+if not base_path.endswith("/"):
+    base_path = base_path + "/"
+
+db = ExplainerDashboard(
+    explainer,
+    url_base_pathname=base_path,
+    routes_pathname_prefix=base_path,
+    requests_pathname_prefix=base_path,
+    title="Model Explainer",
+)
+
+app = db.flask_server()
+```
+
+**requirements.txt** should include at least:
+```txt
+explainerdashboard
+gunicorn
+```
+
+Set your Azure Web App startup command to:
+
+```bash
+gunicorn --bind=0.0.0.0:${PORT:-8000} dashboard:app
+```
+
+Troubleshooting checklist:
+
+1. Open browser dev tools and check network requests to `/_dash-layout` and `/_dash-dependencies`.
+2. If those requests return `404`, fix your base path prefixes (or set `APP_BASE_PATH=/`).
+3. If initial page load is very slow, make sure model training and data loading are not done per request.
+4. Check App Service logs for worker timeouts and increase plan/resources if needed.
 
 It can be helpful to store your `explainer` and dashboard layout to disk, and
 then reload, e.g.: