Faster App Starts by Default
Python/JS apps will start on a pre-built image by default with dependencies already installed, so they are ready in no time.
From 15 October, every app you deploy or redeploy will use the new default backend image (1.7.1 - Python 3.13 + JavaScript (Node 24, Bun 1.3) with optimized resume). On deploy, an image of your app will be built with all its dependencies included. Your app no longer installs packages at every start, so it boots much faster.
What changes
- New or redeployed apps: use the new image and pre-built app images automatically. You don’t need to do anything.
- Apps you don’t redeploy: keep their current image version and behave exactly as before until redeploy.
- Streamlit apps: the default stays the same. A new image with faster starts is available if you want to try it (see below).
How to test your app with the new image
- Open the app and go to the deploy wizard.
- Under Backend version, select
1.7.1 - Python 3.13 + JavaScript (Node 24, Bun 1.3) with optimized resume. - Redeploy. The first deploy builds the image, and later starts use it.
We recommend testing the app after you switch, especially if it has unusual setup steps.
If your app doesn’t work with the new image
You can pin your app to the previous image, so it stays on it even after you redeploy.
- Open the app and go to the deploy wizard.
- Under Backend version, select
1.6.3 - Python 3.11 + JavaScript (Node 20, Bun 1.3) (pinned). - Redeploy.
Faster starts for Streamlit apps
Streamlit apps can use the faster-start image too, but you need to choose it yourself.
- Open the app and go to the deploy wizard.
- Under Backend version, select
3.0.0 - Python 3.13 + Streamlit 1.64 with optimized resume. - Redeploy.
Let us know through a support ticket what went wrong, so we can fix it in the new image.
If you have questions, please submit a support ticket. We look forward to your feedback.