Designing a Service-Oriented Architecture for Merging Legacy US Core Banking Systems with Distributed Ledger Technology

• Abiodun Okunola

  Ladoke Akintola University Technology

  Author

The US banking sector faces a critical juncture as $5 trillion in deposits managed on legacy core banking platforms must reconcile with the imperative for blockchain-based real-time settlement and tokenized assets. While 99% of US institutions now prioritize real-time settlement as a strategic imperative, 55% cite outdated core systems as the primary obstacle to scaling blockchain-based products. This research addresses the gap between legacy infrastructure and distributed ledger technology (DLT) by designing a service-oriented architecture (SOA) that enables enterprise-grade migration without disruptive core replacement. Employing design-based research methodology, the study develops and validates a unified ledger middleware layer that bridges account-based legacy systems with token-based DLT networks. The proposed architecture achieves 89.4% reduction in settlement latency compared to batch-processing baselines, with 99.999% audit trail integrity through cryptographic chain hashing. The framework enables banks to deploy tokenized deposits and programmable payments within existing regulatory frameworks while preserving core system stability. These findings provide a replicable migration pathway for financial institutions, addressing both technical interoperability and operational continuity requirements.

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Copyright (c) 2026 Abiodun Okunola (Author)

This work is licensed under a Creative Commons Attribution 4.0 International License.