title: When to use Google App Engine Flex vs Google Cloud Run
body: <p>I want to deploy containerized code using one of Google's serverless options.  From what I understand Google has two options for this:</p>
  
  <ol>
  <li><a href="https://cloud.google.com/appengine/docs/flexible/" rel="noreferrer">Google App Engine Flexible Environment</a></li>
  <li><a href="https://cloud.google.com/run/docs/" rel="noreferrer">Google Cloud Run</a> (in beta)</li>
  </ol>
  
  <p>I've watched the 2019 Google Next talk <a href="https://www.youtube.com/watch?v=wzPmgWJ5fpU&amp;list=PLIivdWyY5sqLYz6HIadOZHE9PsKX-0CF8&amp;index=6" rel="noreferrer">Where Should I Run My Code? Choosing From 5+ Compute Options</a>.  And I read <a href="https://stackoverflow.com/questions/55619286/what-is-the-difference-between-google-app-engine-and-google-cloud-run">Jerry101's answer to the general question "What is the difference between Google App Engine and Google Cloud Run?"</a>.</p>
  
  <p>To me it basically sounds like Cloud Run is the answer to the limitations of using Google App Engine Flexible Environment.</p>
  
  <p>The reasons I can think of to choose App Engine Flexible Environment over Cloud Run are:</p>
  
  <ul>
  <li><strong>Legacy</strong> - if your code currently relies on App Engine Flex you might not want to deal with moving it</li>
  <li><strong>Track record</strong> - App Engine Flex has been around for a while in general availability and in that sense has a track record, whereas Cloud Run is just in Beta</li>
  </ul>
  
  <p>But those are both operation type considerations.  Neither is a concern for me.  Is there a technical advantage to choosing App Engine Flex over Cloud Run?  </p>
  
  <p>Thanks</p>
  
  <p>Note: The beta Serverless VPC Access for App Engine is only available for the <a href="https://cloud.google.com/vpc/docs/configure-serverless-vpc-access#supported_services" rel="noreferrer">standard environment</a> as of this question posting April 2019, not for Flex, so that's not a consideration in the question of App Engine Flex vs Cloud Run</p>