All dependencies and version numbers are defined in pubscpec.yaml.

e.g.

environment:
  sdk: ">=3.0.0 <4.0.0"
  flutter: "3.10.4"

For Android devices, we have following settings:

compileSdkVersion 33       
minSdkVersion 21
targetSdkVersion 33

Our flutterclient uses null safety and all dependencies use null safety.