title: Google App Engine Standard or Flexible environment?
body: <p>I am stuck in deciding between choosing Google App Engine Standard Vs. Flexible environment for a real world production. I want to use Java definitely. Need to use Firebase(latest version) for Authentication and Push notification; I'm not sure whether new Firebase is compatible with standard or flexible.</p>
  
  <p>per the caution note in the following link, my impression is that recent Firebase is compatible is with Flexible Environment only.</p>
  
  <p><a href="https://cloud.google.com/solutions/mobile/firebase-app-engine-android-studio" rel="noreferrer">https://cloud.google.com/solutions/mobile/firebase-app-engine-android-studio</a></p>