How should kitchen walls be prepped before an interior repaint

On a wall behind a range, the surface is not painted drywall anymore, it is a thin film of cooking oil with paint under it. The running record torrance interior painting high level center holds shows kitchen repaints failing at the bond layer, not in the paint, and interior painting in Torrance, CA is no different. Homes near the Del Amo Fashion Center area and across the South Bay that have been cooked in for thirty years carry that film on every wall, even where it cannot be seen.
Test for grease first

A white cloth wiped over the wall near the stove will come away yellow or tan if oil is present. Water beaded on the surface instead of soaking in is the same sign. Paint applied over grease will peel in sheets or fish eye into small craters, and no amount of extra coats corrects it.
Degreasing the right way

A strong degreaser, mixed to the label and applied with a sponge, is worked across the lower walls, the area around the range hood and the cabinet faces if they are being painted. Then comes a clean water rinse, because leftover degreaser is itself a bond breaker. The wall dries fully, usually a few hours, before anything else happens.
Patching and scuff sanding
Nail holes, anchor holes from old shelves and dings near the doorway are filled with spackle and sanded flush. Larger holes get a mesh patch and joint compound in two passes. A scuff sand over the whole wall dulls the old sheen. Satin or semi gloss left from the last repaint will not hold a new coat without it, since paint needs microscopic tooth to grab.
Primer where it counts
Every patch is spot primed, or the filled areas show as dull, textured blotches under the finish, the flashing painters try hard to avoid. Walls with stubborn staining near the stove or sink get a full coat of bonding primer, oil based or an acrylic stain blocker. Smoke and grease stains will otherwise creep through two coats of latex.
Washable sheen and coats
Kitchens take wiping, so eggshell is the floor and satin is the common pick on walls, with semi gloss on trim and any cabinet enamel. Flat paint is never right here. Two coats of acrylic latex go on, the first cut in around cabinets and windows with a brush, then rolled with a medium nap roller. Coverage on a primed wall is even, and the second coat settles the sheen.
Cabinets and trim
Cabinet boxes and doors need their own degrease, deglossing and a bonding primer before an enamel topcoat. Hinges and pulls come off and go back after the paint has hardened for a day.