This wall and ceiling were damaged from a roof leak. [ i can do spot roof repairs ] After the leak was fixed, the damaged wall and ceiling was removed, and the area allowed to dry out. Fiberglass mesh was then applied to the damaged areas, and spackle was applied in several layers. This type of repair takes several days, as you have to let each layer of spackle dry before applying the next layer.
Repairs like this are difficult to make look perfect, as the building settles, the walls are not square and true, and there is difference between the texture of the original wall and the repaired area.