Optimization workflow for comprehensive design and loss estimation in superconducting circuits

We present a workflow that integrates with KQCircuits to enable comprehensive modeling and optimization of superconducting quantum processors. The approach connects device design, modeling, and performance evaluation within a consistent workflow. This integration supports closed-loop QPU design optimization, where design parameters and performance metrics can be used to improve coherence, reduce losses, and achieve scalable device architectures. By linking simulation, modeling, and quantum characterization, the workflow accelerates development cycles and strengthens the connection between device physics and quantum-level functionality. The workflow led to an about 1.6-fold improvement in the T1 of the central resonator in a prototype of our star-topology architecture, consistent with the predicted enhancement. This work highlights advances in computational design methodologies that foster efficient, reproducible, and collaborative progress in superconducting quantum hardware development.