A damper seal for a gas turbine engine includes a damper body extending in a first direction between a leading edge portion and a trailing edge portion, extending in a second direction between first and second sidewalls, and extending in a third direction between a convex outer damper face and a concave inner damper face. The inner damper face establishes a damper pocket. The leading and trailing edge portions slope inwardly from opposite ends of the damper body to bound the damper pocket in the first direction. The first and second sidewalls extend from the leading edge portion to the trailing edge portion and slope inwardly from opposite sides of the damper body to bound the damper pocket in the second direction. The outer damper face is pre-formed according to a first predetermined geometry that substantially corresponds to a second predetermined geometry of a platform undersurface bounding a neck pocket of an airfoil. A method of damping for a gas turbine engine is also disclosed.