According to an embodiment of the present invention, a method of producing a quantum computer chip includes performing a frequency measurement on a qubit chip bonded to a test interposer chip for qubits on the qubit chip at an operating temperature of the qubit chip. The method further includes pulling the qubit chip apart from the test interposer chip after performing the frequency measurement, and modifying a frequency of a subset of qubits after pulling the qubit chip apart from the test interposer chip. The method further includes bonding the qubit chip to a device interposer chip after modifying the frequency of the subset of qubits.