This should not differ from other apps, in what concerns deployment, so you'll be able to find needed information on the "Building a Node.js App on App Engine" guide
page. Often, one can get more insight following a
quickstart, in this case "Quickstart for Node.js in the App Engine Standard Environment".
This discussion group is oriented more towards general opinions, trends, and issues of general nature touching App Engine and Cloud SQL. For coding and programming architecture in Node.js, you may find yourself better served in dedicated forums such as stackoverflow, where experienced programmers are within reach and ready to help.