From Legacy to Cloud: Migration Strategies for Traditional Financial Institutions Using AWS

Traditional financial institutions face unprecedented pressure to modernize their technological infrastructure while maintaining regulatory compliance and operational stability. This research examines the strategic approaches, implementation challenges, and outcomes of migrating legacy banking systems to Amazon Web Services (AWS) cloud infrastructure through a mixed-methods analysis of twelve financial institutions that completed migrations between 2019 and 2024. Through structured interviews with technology leaders and quantitative analysis of migration outcomes, including regulatory considerations and real-world implementation cases, this study identifies key success factors and potential pitfalls in large-scale financial services cloud adoption. The research reveals that institutions adopting phased migration strategies with robust risk management frameworks achieve 92% success rates with 30-45% cost reductions and 40-60% performance improvements, compared to 58% success rates for rapid, wholesale transitions. Furthermore, the study demonstrates that AWS-specific services such as AWS Control Tower and AWS Config provide essential governance capabilities that traditional financial institutions require for regulatory compliance during cloud transformation initiatives.