Azure App Service: Extracting a 60MB node_modules ZIP takes longer than running npm install — how to speed this up?

I have an automated deployment tool that generates a React or Angular project, uploads it to Azure App Service, and then restores node_modules to reduce build time.

To avoid running npm install on every deployment, I store a prebuilt node_modules.zip (~60 MB) in Azure Blob Storage.
My workflow is:

1. Download node_modules.zip

2. Extract it inside Kudu (App Service console) under /tmp/...

3. Copy the extracted folder to /home/site/wwwroot/<project>/node_modules

The problem:
Extracting + copying this ZIP takes more time than running npm install, even though the whole idea was to speed up deployment.

What I tried

• Using node_modules.zip

• Extracting to /tmp then copying to the project directory

• Trying different unzip packages (unzipper, adm-zip, etc.)

• Using Kudu console and Azure CLI

Issues Observed

• Azure App Service file system is slow with thousands of small files

• Zip extraction of node_modules is extremely slow

• Copying the folder doubles the delay

• End result: npm install actually finishes faster

  My Question

  How can I speed up the node_modules restore process on Azure App Service?

  I want to avoid running npm install every time, but extracting a ZIP of node_modules is even slower. What’s the best practice to quickly restore dependencies on Azure App Service?

  Additional Notes

  • App Service is Linux-based

  • Deployment tool is using Node.js

  • React and Angular builds are working, this issue is only with node_modules restore

  • I am open to alternatives like tar.gz, npm cache, npm ci, etc.

  What I am looking for

  • Better format to store node_modules (tar.gz?)

  • Faster extraction method

  • Extract directly to destination without copy?

  • Alternative approaches (npm cache or npm ci)

  • Any best practices for dependency restore in Azure App Services