There's nothing particularly special about Lambda's scaling. You can do the same with GCP Cloud Run[0] or Azure Container Apps[1]

Specify the maximum number of allowed instances and maximum concurrency per instance. Optionally configure more targeted scale rules. It will scale it from 0 - n as needed.

[0] https://docs.cloud.google.com/run/docs/about-instance-autosc...

[1] https://learn.microsoft.com/en-us/azure/container-apps/scale...