Automate creation of a managed instance group whose VMs have many OS package dependencies while minimizing VM startup time. What should you do?

Building a custom VM image with all necessary OS packages pre-installed is the most efficient way to minimize VM startup time. When a new VM instance is created from this image, it doesn't need to download and install packages during boot, significantly reducing the provisioning time. Deployment Manager is an appropriate tool for defining and deploying the managed instance group using this custom image. Using startup scripts (Terraform, Puppet, or Ansible) to install packages at boot will increase startup time because each VM will execute these installations individually. While these tools are excellent for configuration management, for minimizing boot time with many dependencies, a pre-baked image is superior.