Optimizing Legacy Systems for Cloud Migration: Patterns and Pitfalls in AWS Transition

Legacy systems, while foundational to many enterprises, increasingly hinder agility, scalability, and cost-efficiency in today’s digital landscape. Cloud migration particularly to Amazon Web Services (AWS) offers a path to modernization, but the journey is fraught with architectural, operational, and organizational challenges. This paper explores the strategic optimization of legacy systems during AWS migration, emphasizing established migration patterns such as rehosting, replatforming, and refactoring. Drawing from real-world implementations, I analyze common pitfalls including data integrity issues, cost overruns, security vulnerabilities, and resistance to change. I also present best practices for pre-migration assessment, infrastructure automation, and post-migration performance tuning. Special attention is given to AWS-native tools and services that support a secure, efficient transition. The article provides actionable insights for IT leaders, architects, and decision-makers. This research aims to demystify the AWS migration process and offer a roadmap for organizations seeking to transform legacy systems into scalable, cloud-native solutions while minimizing disruption and maximizing return on investment.