Looks SDF-ish. My guess is convert the letters to curves, cut them into pieces without holes so each piece is the set of points between certain curves, write do

Looks SDF-ish. My guess is convert the letters to curves, cut them into pieces without holes so each piece is the set of points between certain curves, write down SDFs for each curve (negative on the "inside", positive on the "outside"), combine all SDFs in a piece with intersection (max), then combine all pieces with union (min).