§ 02 · AS-P02
Double stack: global execution, local decision
An inviolable decision layer; a modernizable execution layer.
Statement
The execution layer can integrate with global technological infrastructure; the decision layer must remain under sovereign control. The line between them is the operational frontier of modern sovereignty.
Why it matters
Technology providers have a growing incentive to integrate decision logic within their models, because it raises switching costs and consolidates dependence. When a tax agency adopts an AI model that not only processes returns but also decides which ones are suspicious, it is outsourcing a political decision — what counts as fraud — to a contractually external black box. When a bank adopts a credit scoring system that not only applies criteria but defines them within its own internal logic, it is delegating to a vendor the decision of who accesses credit and under what rules. The consequence is that the operational logic of the State, company or region progressively merges with the vendor's logic, until the distinction between «what the actor decides» and «what the platform decides» becomes, in practice, undecidable.
Operationalization
Every implementation of AI or algorithmic systems must explicitly document two columns: what components are executed by external providers (foundation models, compute, data infrastructure) and what components are defined and controlled locally (taxonomies, decision criteria, action-triggering thresholds, appeal logic, audit structure, exception criteria). Control over the second column must be technically real, not contractual: the organization must be able to modify those components without provider permission, must be able to audit them without requesting access, and must be able to migrate them to another provider if necessary. A decision layer that exists only in the operator's mind or in contractual clauses is not under control: it lives at the provider's discretion.
Named tension
Operational efficiency typically requires deep integration, and deep integration erodes the separation between the two layers. There is a structural trade-off: the more deeply a system is integrated, the more efficient it is and the more expensive subsequent separation becomes. Sustaining the double stack means deliberately giving up some short-term efficiencies in exchange for long-term operational sovereignty.
Applied example
A ministry defines that digital citizen identity is decision layer (not delegated) and that batch compute hosting is execution layer (can live on any cloud). The compute contract is renegotiated annually; identity is never outsourced.
AS-P02·v1.0·May 2026arquitecturasoberana.com/en/el-marco/principios/double-stack