Google App Engine is a Platform as a Service (PaaS) offering that allows you to quickly deploy your applications. The app engine environment automatically scales your app up or down depending on the load. You can also customize the runtime and the operating system of your app engine using Docker files.
App engine offers two different environments, the flexible environment and the standard environment. Depending on your use case, you can choose to use both environments simultaneously for your application.
The following table summarizes the differences between the two environments:
| Feature | Flexible environment | Standard environment |
| Instance startup time | Minutes | Seconds |
| Maximum request timeout | 60 minutes | 60 seconds |
| Background threads | Yes | Yes, with restrictions |
| Background processes | Yes | No |
| SSH debugging | Yes | No |
| Scaling | Manual and automatic | Manual, basic... |