We need to replace our deck which is outside our living room and dining room-ranch home-looks like one level from front, but the house is on a hill so the deck in the back is a second story one. Does that make sense?

Anyway, we have doors and full length windows across the back going to the deck. The windows and doors need to be replaced as well.

Chances are we will have different contractors for the two jobs, so does it matter which is done first? We have had leaking in the downstairs when we get heavy rain, so I imagine that is being caused either by the flashing being insufficient or the doors leaking. Not sure which it is. Both the deck and the doors/windows are about 25 years old. I will attach a photo that shows one of the door/window sections and the stationary window, with the second door which has a window at the far end like the unit on the right.

Thanks so much. I am just not sure where to start.

Found one from the exterior, too, in case that helps.