Sage Dynamics is a training company that travels the US. Their course catalog includes handgun, rifle, red dot and force on force training. They also offer low light and night vision courses.
Sage Dynamics is run by Aaron Cowan, who has had a YouTube channel for quite a while. His channel focuses on gear reviews and information. While this sounds like every other gun-tuber, Sages information is well presented, thought out and appears to be very honest.
His notoriety comes, in part, from his testing protocol for law enforcement optics. His testing calls for 2000 rounds of hard use, including a 500 round "burn down", and a drop from shoulder height on the optic every 500 rounds. His testing and evaluation of other equipment is also very good, but his training videos are also quite good.
Check out the channel and check out Sage Dynamics when looking for training this year!