space-server | Navigation of three dimensional parameter space | Addon library

TLDR: Sorry for the longest question in history, but I hope this is comprehensive for any users having a similar problem. My app deploys successfully from cloud shell to my domain; however, when I try cloud build, I get Cannot find module '/workspace/server.js' The error likely has to due with my build handlers in the app.yaml, or something to do with my cloudbuild.yaml.

Solution: use the right handlers in app.yaml standard and properly set up your cloudbuild.yaml

I am having trouble using App Engine and Cloud Build together. I am using Cloud Build to set up CICD with my Github repo. I think the issue is due to the fact that I have been not been deploying the production build to app engine. I was able to successfully deploy manually (dev version) with:

gcloud app deploy

Now, I am having trouble with my Cloud Build. In particular, I am trying to run flex environment, but I keep getting "Neither "start" in the "scripts" section of "package.json" nor the "server.js" file were found." But my package.json has a startup script?

I also tried standard environment instead of flex, but I couldn't get the handlers figured out. I tried dozens of examples. I have included the standard environment app.yaml so you can see it.

Here's my package.json: