Embodiments herein describe techniques for an IC package including a package substrate. The package substrate includes a set of validation connectors formed on a first side of the package substrate, a first set of functional connectors formed on the first side of the package substrate, and a second set of functional connectors formed on a second side of the package substrate opposite to the first side. A validation connector of the set of validation connectors is arranged to be coupled with a validation connector of an IC die placed above the first side of the package substrate. A first functional connector of the first set of functional connectors is arranged to be coupled with a functional connector of the IC die. A second functional connector of the second set of functional connectors is arranged to be coupled through the first functional connector to the functional connector of the IC die.