It does work with Rails 5! I've had luck with it, but you will want to make sure that you have pretty good test coverage to make sure stuff doesn't break. Goldiloader is pretty awesome, but it does add a bit too much 'magic'. The proper/better solution is to fix the performance gaps in the code rather than relying on the gem. However, if you do want to give it a shot, I've had luck with v0.0.12 and still getting passing tests. I think there was an issue on v2.0.0. It might have since been resolved.