An article of manufacture, wherein the article of manufacture is a turbine blade or a turbine vane, wherein the article of manufacture comprises: at least one platform of the turbine blade and the vane, respectively; one or more airfoils extending span-wise from the platform; wherein each of said one or more airfoils comprises an outer wall formed of a pressure side and a suction side joined at an airfoil leading edge and at an airfoil trailing edge, wherein the platform extends from a platform leading edge to a platform trailing edge, wherein the platform comprises a first mate face and a second mate face spaced along a pitch-wise direction, the first mate face being proximal to the suction side of one of the airfoils and the second mate face being proximal to the pressure side of the same airfoil or a different airfoil of said one or more airfoils, the first and second mate faces extending between the platform leading edge and the platform trailing edge, wherein the first mate face is chamfered or filleted along an aft portion thereof, the chamfered or filleted portion of the first mate face extending from the platform trailing edge to a first intermediate point on the first mate face located between the platform leading edge and the platform trailing edge, wherein the first and the second mate faces have a wavy contour in a direction from the respective platform leading edge to the respective platform trailing edge, wherein the wavy contour comprises a radial amplitude, wherein a chamfered or filleted portion (36, 38) of the first mate face and the second mate face have a chamfer or filleted surface (50, 60; 50', 60'), wherein the chamfer surface (50, 60) of the first mate face and the second mate face extends radially from a first chamfer edge (52, 62) to a second chamfer edge (54, 64) of the first and the second mate faces at a chamfer angle (α 1, α 2) with respect to the radial direction R, and wherein the filleted surface (50', 60') of the first mate face and the second mate face comprises a rounded surface (50', 60') extending between a first and second fillet edge (52, 62; 54, 64), wherein the chamfer or filleted surface (50, 60; 50', 60') of the first mate face and the second mate face follows said wavy contour, wherein the first chamfer edge (52, 62) is parallel to the second chamfer edge (54, 64) and the first fillet edge (52, 62) is parallel to the second fillet edge (54, 64). at least one platform of the turbine blade and the vane, respectively; one or more airfoils extending span-wise from the platform; wherein each of said one or more airfoils comprises an outer wall formed of a pressure side and a suction side joined at an airfoil leading edge and at an airfoil trailing edge, wherein the platform extends from a platform leading edge to a platform trailing edge, wherein the platform comprises a first mate face and a second mate face spaced along a pitch-wise direction, the first mate face being proximal to the suction side of one of the airfoils and the second mate face being proximal to the pressure side of the same airfoil or a different airfoil of said one or more airfoils, the first and second mate faces extending between the platform leading edge and the platform trailing edge, wherein the first mate face is chamfered or filleted along an aft portion thereof, the chamfered or filleted portion of the first mate face extending from the platform trailing edge to a first intermediate point on the first mate face located between the platform leading edge and the platform trailing edge, wherein the first and the second mate faces have a wavy contour in a direction from the respective platform leading edge to the respective platform trailing edge, wherein the wavy contour comprises a radial amplitude, wherein a chamfered or filleted portion (36, 38) of the first mate face and the second mate face have a chamfer or filleted surface (50, 60; 50', 60'), wherein the chamfer surface (50, 60) of the first mate face and the second mate face extends radially from a first chamfer edge (52, 62) to a second chamfer edge (54, 64) of the first and the second mate faces at a chamfer angle (α 1, α 2) with respect to the radial direction R, and wherein the filleted surface (50', 60') of the first mate face and the second mate face comprises a rounded surface (50', 60') extending between a first and second fillet edge (52, 62; 54, 64), wherein the chamfer or filleted surface (50, 60; 50', 60') of the first mate face and the second mate face follows said wavy contour, wherein the first chamfer edge (52, 62) is parallel to the second chamfer edge (54, 64) and the first fillet edge (52, 62) is parallel to the second fillet edge (54, 64).