SDIS-10 — Public-Sector Cloud Procurement: Governance Models for Sovereign Technology Adoption Sovereignty is ultimately enforced or abandoned at the procurement contract, not the architecture diagram — the strongest technical design fails if the contract governing it grants the vendor unilateral termination rights, opaque subcontracting, or no verified exit path. This paper specifies a governance model for public-sector (and sovereignty-sensitive private-sector) technology procurement, tracing the history of public-sector technology procurement as a discipline. The paper covers vendor qualification criteria mapped to the four-plane framework in SDIS-01, exit-strategy and portability requirements, procurement vehicle design, and an oversight structure for ongoing verification rather than point-in-time certification. It presents sixteen case studies drawn from composite and anonymized procurement review experience, addresses eight common objections, and closes with economic and organizational considerations, a seven-phase implementation roadmap, a glossary, and a self-assessment checklist. Keywords: procurement, public sector IT, vendor lock-in, exit strategy, governance This is Paper 10 of 12 in the Sovereign Digital Infrastructure Series (D-AI), translating the four-plane framework from SDIS-01 and the sovereign cloud patterns in SDIS-02 into contractual and procurement practice, and connecting to the cross-border governance treaties in SDIS-11. A companion series guide (SDIS-00) provides a full cross-citation map, publication registry, and licensing terms for all papers. Series: Sovereign Digital Infrastructure Series (SDIS) · Publication: SDIS-10 · Author: Bijan Burnard · Affiliation: D-AI Research · Version: 1.0 · Publication Date: 23 August 2026 · ISBN: 978-969-9597-38-1 · DOI: 10.5281/zenodo.22085554 · License: CC BY 4.0