The function of the tools I use and how they work are explained here. Specific tools used are noted in bold.
The doors are constructed using a combination of three types of joints. Rails are the horizontal pieces, and stiles the vertical.
The rails and stiles join using cope and stick joints. Mirror image router bits cut mating profiles that slide together. This aligns the pieces and adds joint strength.
The arch and vault tops are joined to their stiles using the inner ply as a spline. A matching dado grove is cut in the stiles to receive the splines.
The main strength comes from the domino joints. The domino cutter is used to cut elongated slots. A wooden domino is glued in the slots. The dominos on the doors are 5 ¼” long, which provides lots of strength.