Old Heroku website keeps stuck at Building phase during deployment

@cyz It will be because your npm run build script executes node server.js.

Netlify and Heroku aren’t the same, and you cannot run a “server” with Netlify.

See:

The reason it is “in progress” for a very long time during the build phase is because you aren’t building anything, you’re starting a server which then runs until the maximum execution time is reached and it turns off.