[amelius]

> this blog post made me feel like "those guys are doing black magic".

Two remarks. First, these guys probably don't know very well why what they are doing works so well ;) It requires a lot of trial and error, and a lot of patience and a lot of compute power (the latter being the reason why we are seeing breakthroughs only now).

Second, training a neural net requires different computing power from deploying the net. The neural network that is installed on your phone has been trained using a lot of time and/or a very large cluster. Your phone is merely "running" the network, and this requires much less compute power.