From fab to fridge: processing and infrastructure for reproducible high-coherence qubits

Reproducibility and robustness are essential for enabling the transition of superconducting quantum processors from research prototypes to scalable, deployable systems. We present insights from commercially fabricated aluminium-based transmon devices deployed across multiple independent facilities, consistently exhibiting high coherence under diverse cryogenic and microwave conditions. Our qubits reach energy relaxation times T1 up to 140 µs on average, with highest values up to 250 µs. We also reach T1-limited spin-echo decoherence times T2e in both tunable and fixed-frequency qubits. We achieve high reproducibility in both coherence and frequency targeting across devices fabricated with various Josephson junction technologies - including Dolan bridge and Manhattan-style geometries - over a wide range of designed junction resistances. By systematically studying devices with varying levels of circuit and packaging complexity, we identify the design, fabrication, and cryogenic microwave measurement setup parameters most strongly correlated with coherence. We highlight process controls that yield stable junction performance and discuss best practices for packaging, shielding, filtering, and long-term device storage. Together, these results demonstrate that long-term, reproducible, high-coherence operation can be achieved and maintained across environments on a commercial scale.