There just aren't very many people on the forum who can give a proper critique, may have to wait a bit.
Meanwhile, I would try to get a better pic - out of the shadows, standing on level ground, feet visible, looking forward instead of the camera, if you can.
A proper critique may shoot down my comment, but from the little I know, he has a nice level top with flat withers (flat withers is a fault - the smooth level back is not.
). The croup could curve down some more (he is built like a box). Very nice TIGHT feet (a plus!), nice pasterns. Looks to me like he could have more angulation in the rear, but it could be just how he is standing. A proper stack would help.
Big blocky head on him, strong masculine features.
He is still in the young teen wonky stage, so his conformation may still change as he grows up.
For stacking, most people just physically move the dog's legs into the position they want and tell them to stay/stand. Put a toy or treat on a chair in front of him out of the picture to get him to look and focus ahead.