Faster Heroku deploys with Rails and webpacker

Some time ago in Pilot, we switched to use webpacker as a tool for compiling our JavaScript code. It is a simple way to integrate webpack into your Rails project.Lately, we noticed that our Heroku deploys got frustratingly long. Over 10 minutes to build and release our main application wasn't acceptable. Add CI runtime and Heroku's preboot to the mix and now we could easily end up with around 25-30 minutes of full deploy time. This was getting very annoying when trying to ship a hotfix.What if we could make it shorter?.