Make login credentials ephemeral.
    
      
 On Android:
        
          Remove the json_key_file field from Appfile and store the string
content of the JSON in your CI system’s encrypted variable. 
Read the environment variable directly in your Fastfile.
            
upload_to_play_store(
  ...
  json_key_data: ENV['<variable name>']
)
            
          
          Serialize your upload key (for example, using base64) and save it as
an encrypted environment variable. You can deserialize it on your CI
system during the install phase with
            
echo "$PLAY_STORE_UPLOAD_KEY" | base64 --decode > [path to your upload keystore]
            
          
        
      
      
 On iOS:
        
          Move the local environment variable FASTLANE_PASSWORD to use
encrypted environment variables on the CI system.
          The CI system needs access to your distribution certificate.
fastlane’s Match system is
recommended to synchronize your certificates across machines.