Migrating Legacy Information Management Systems to AWS and GCP: Challenges, Hybrid Strategies, and a Dual-Cloud Readiness Playbook

Legacy Information Management Systems (IMS) remain central to operations in banking, healthcare, public sector, and media, yet their monolithic design, proprietary data formats, and brittle integrations have become barriers to agility and intelligent analytics. Earlier literature identified the persistent costs and risks of legacy IMS and proposed incremental modernization through wrapping, service extraction, and reengineering, while empirical studies in the early 2010s established the feasibility and business value of infrastructure-as-a-service (IaaS) rehosting. As of late 2017, however, the migration decision space has widened: enterprises are not merely choosing whether to move to the cloud, but how to distribute workloads across multiple hyperscalers, primarily Amazon Web Services (AWS) and Google Cloud Platform (GCP). This article synthesizes more than a decade of academic and industrial work on legacy migration and proposes a Dual-Cloud Readiness Playbook tailored to IMS modernization. The playbook comprises a readiness scorecard, a five-phase migration lifecycle, and a layered hybrid architecture that balances compliance, cost, and capability while reducing vendor lock-in. The result is a pragmatic framework that aligns with the realities of petabyte-scale content archives, metadata-heavy workflows, and emerging regulatory constraints, offering a credible path from monolithic legacy platforms to modern, cloud-native information management