Multi-level SLI/SLO model for critical financial infrastructure: linking technical metrics to business scenarios

Abstract

The reliability of critical financial infrastructure has become a strategic imperative as digital payment platforms, central bank digital currencies (CBDCs), and real-time settlement systems expand globally. This article investigates the theoretical foundations and practical application of a multi-level Service Level Indicator (SLI) and Service Level Objective (SLO) model designed specifically for critical financial infrastructure environments. The study examines how technical observability metrics can be systematically mapped to business scenarios, regulatory compliance requirements, and operational continuity objectives. Using a comparative analytical framework and case-study evidence drawn from CBDC integration practice at a systemically important bank, the research demonstrates that hierarchically structured SLI/SLO contracts, combined with AI-driven observability, reduce mean time to recovery (MTTR) by an order of magnitude and enable proactive error budget management. The findings reveal that a four-layer SLI/SLO hierarchy covering business outcomes, service contracts, component metrics, and infrastructure signals is necessary and sufficient for aligning engineering reliability work with financial regulatory mandates. The article will be of interest to financial technology architects, reliability engineers, banking regulators, and researchers working at the intersection of distributed systems engineering and financial services compliance.