In March 2026, a consortium in Denver assembled a working quantum computer from five different vendors’ components in five months. A Dutch QPU, Dutch control electronics, an American cryostat, Australian calibration software, and a global supply chain partner — integrated into a cloud-accessible machine for under $8 million. A year earlier, the same capability would have required a $50 million commitment to a single vertically integrated vendor.

That build proved a thesis: quantum computers can now be assembled the way servers, aircraft, and data centers are assembled — from independently sourced, best-of-breed components managed by a systems integrator. The Quantum Open Architecture (QOA) model has moved from concept to operational reality, and three additional multi-vendor builds in Delft, Munich, and Naples have confirmed the pattern.

At the same time, governments worldwide committed billions not to quantum research but to quantum manufacturing. The US CHIPS Act committed $2 billion. France brought its total to €3.3 billion. The UK announced £2 billion through ProQure. Australia backed PsiQuantum with AU$940 million. EuroHPC deployed six quantum computers across European supercomputing centers. The era of funding physics papers is over. The era of funding quantum factories has begun.

These two developments create a gap. The money is flowing. The components exist. But no book tells a CTO, laboratory director, or defense procurement officer what they need to know to act. Quantum Systems Integration fills that gap. Inside, you will find:

• How the Quantum Open Architecture model works in practice — the six-layer stack, the vendor ecosystem, and why disaggregation changes the procurement calculus for every buyer evaluating quantum compute hardware
• What it takes to build a superconducting quantum computer from modular components — the signal chain from room temperature to 10 millikelvin, the cryostat selection, the control electronics, the cabling, and the calibration software that compresses bring-up from months to weeks
• How trapped-ion, neutral-atom, photonic, and silicon-spin builds differ — facility requirements, vendor options, integration timelines, and where each modality fits in the procurement decision
• What a quantum computer actually costs — capital expenditure tiers from $2 million to $150 million, line-item breakdowns, five-year total cost of ownership models, and the personnel costs that surprise every first-time buyer
• The supply chain constraints that determine your timeline — helium-3 structural deficits, cryogenic I/O density limits, dilution refrigerator lead times, and FPGA allocation bottlenecks
• How to integrate quantum compute resources with existing HPC infrastructure using NVQLink, QRMI, and Slurm-native scheduling — and why the Western quantum software stack is a strategic vulnerability
• A step-by-step integration sequence from procurement to first qubit signal, including facility preparation, the OCP QPU Deployment Checklist, commissioning procedures, and SLA acceptance criteria
• Government funding programs across 15+ countries — how to structure applications, which programs fund hardware versus research, and how to align procurement timelines with grant cycles

Marin Ivezic is the founder of Applied Quantum, the first professional services firm dedicated exclusively to quantum technologies. Over a career spanning more than 25 years, he has founded multiple quantum ventures — including Boston Photonics and PQ Defense — and built and led quantum advisory, cybersecurity, and geopolitical risk practices within several of the world’s largest professional services firms. He has served as a Fortune Global 500 CISO and CTO, held cybersecurity leadership roles at PwC, KPMG, IBM, and Accenture, and advised thirteen nations on national cybersecurity strategy. Marin is a SANS Institute instructor and the author of PostQuantum.com, one of the most widely read sources on quantum security and quantum strategy. His previous book, The Future of Leadership in the Age of AI, was an Amazon bestseller and has been cited for its prescient analysis of trends now unfolding across industries and governments worldwide.