ENTERPRISE INTEGRATION LESSONS FROM FOUR DIGITAL FRONTLINES: A COMPARATIVE ANALYSIS OF MODERN IT ECOSYSTEMS

Enterprise integration is a vital enabler of digital transformation in complex environments with legacy systems, diverse stakeholders, and evolving technologies.This study examines integration strategies across four major digital transformation efforts-NHS Digital (UK), DBS Bank (Singapore), Estonia's e-Governance, and Maersk's TradeLens platform.Using a comparative case study approach, we assess integration architectures, middleware, protocols, and governance using a capability framework based on system decoupling, API management, real-time synchronization, identity federation, and orchestration.Key enablers include microservices, API gateways, and event-driven messaging (e.g., Kafka).Success factors extend beyond technology to include governance mechanisms like role-based access control (RBAC), integration SLAs, and CI/CD-aligned DevOps pipelines.Findings highlight the effectiveness of lightweight, domain-specific integration layers, the importance of standardized semantics (e.g., HL7 FHIR, ISO 20022), and Mutha Ravi Tej Kotla https://iaeme.