From Prototype to Reusable Financial Infrastructure: An Open-Source Reference Architecture

Abstract

Financial microservices repeatedly implement identity checks, authorization, request validation, audit recording, and deployment configuration. A successful local demonstration does not establish that these controls remain correct when components are reused by another team or combined with a different identity provider, database, or operating environment. This article investigates how individually developed financial security components can evolve into reusable, interoperable, documented, and independently evaluable infrastructure. It proposes the Open Financial Security Reference Architecture (OFSRA), a nine-layer design that connects security interfaces, financial domain adapters, operational evidence, verification, and documentation through explicit acceptance contracts. The implementation analysis examines the public secure-distributed-systems-lab repository at commit 740dc75b77f24118110935e174bf2f8167833ab7, the latest qualifying main-branch revision identified before the June 30, 2026 technical cutoff. Source inspection establishes JWT validation, role checks, validated configuration, local structured audit recording, and an in-memory transaction example. Gateway, login, database audit, and container artifacts provide incomplete integration foundations. Missing shared modules, inconsistent build targets, and limited tests prevent a claim of a complete deployable framework. OFSRA therefore separates verified component behavior from proposed identity federation, tenant-aware policy, durable audit processing, and portable deployment. Its contribution is an evidence-linked transformation methodology and evaluation protocol rather than a new security primitive or a demonstrated performance improvement. The resulting approach gives external engineering teams concrete procedures for assessing replacement boundaries, security decisions, failure behavior, integration effort, and adoption readiness before adapting financial infrastructure.