This article explores how Generative AI (GenAI) is revolutionizing legacy application modernization in enterprise environments. Legacy systems, with their outdated technologies and rigid architectures, represent significant technical debt and maintenance burdens for organizations. GenAI-powered agents are emerging as transformative tools that can analyze complex codebases, discover implicit knowledge, recommend customized modernization strategies, and automate code transformation. The article examines core capabilities of these AI agents, including automated code analysis, intelligent strategy formulation, code transformation, and API generation. It presents implementation approaches across assessment, execution, and governance phases, supported by case studies from financial services, healthcare, and manufacturing sectors that demonstrate substantial improvements in modernization speed, cost, and outcomes. As these technologies continue to evolve, they promise to fundamentally reimagine how organizations approach technical debt and enable more adaptive, innovative technology landscapes
Keywords: Legacy modernization, autonomous agents, code transformation, generative AI, technical debt
