Not too much specific is known about it, but these two quotes I found after a quick search gave some info:
“Too Old to Die Young” stars Miles Teller as a grieving police officer forced to investigate Los
Angeles’ criminal underworld, which includes working-class hit men, Yakuza soldiers, cartel assassins sent from Mexico, and Russian mafia captains."
and from Ed Brubaker
“The show will launch in the spring, I believe, on Amazon. Nic and Matt [Newman, editor] are still cutting the second half of the season, but what I’ve seen is amazing. It’s the most Nicolas Winding Refn thing that ever existed, honestly. It’s stylish and shocking, it has some of the best cinematography ever for television (our lead DP
was the great Darius Khondji, so of course it does), and at the same time it is a meditation on these characters trapped in this world that’s not too unlike the world all around us, that feels like it’s about to fall apart, or maybe be torn apart…It’s also the most exhausting thing I’ve ever done, writing that show with Nic. We had a 10-month shoot, which I think might be a record, with one director shooting it all.”
To me it sounds like a stylized crime drama.