npm start, webpack build memory usage exceeds 500MB

[jonathankenbrown]

This is more of discussion rather than issue report.
Is there a suggested way to decrease the memory usage while the webpack is building? Just to run this example, even in NODE_ENV=production, memory usage exceeds 550MB. Once the build is complete, of course, it drops to ~25MB.
I have a problem deploying a small test app to Heroku, as they're only providing me with 512MB and build exceeds 10s while it switches over to swap space.

Please, any hint is appreciated! Great project.