McKinsey’s AI platform slashes legacy system modernization time by 80 percent

McKinsey’s LegacyX platform harnesses the power of generative and agentic AI to transform aging digital infrastructure that hampers innovation in large organizations. This breakthrough approach tackles a widespread challenge—70 percent of Fortune 500 software was developed over two decades ago—by accelerating modernization efforts by up to 80 percent while reducing costs. Beyond technical upgrades, the platform also intelligently reengineers underlying business processes that have been tailored to legacy systems over decades, addressing a critical but often overlooked dimension of digital transformation.

The big picture: Legacy infrastructure remains a significant barrier to digital innovation for large enterprises, requiring massive investments of time, money, and engineering talent to modernize.

• Traditional modernization efforts face prohibitive costs, multiyear timelines, and the risk of becoming obsolete before completion.
• The entanglement of business processes with legacy systems adds another layer of complexity, as workflows developed over decades require significant re-engineering to work with modern technology.

Key innovation: McKinsey’s QuantumBlack AI division has developed LegacyX, a proprietary platform leveraging autonomous AI agents to drastically accelerate and simplify infrastructure modernization.

• The platform can reduce modernization timelines by up to 80 percent while simultaneously lowering costs and resource requirements.
• Beyond upgrading technology, LegacyX analyzes and adapts workflows to ensure business processes integrate seamlessly with modern infrastructure.

Why this matters: Aging digital infrastructure represents a hidden tax on innovation across virtually every industry, with most large organizations struggling to maintain competitiveness while tied to decades-old systems.

• The dual-pronged approach of modernizing both technology and business processes addresses the comprehensive challenge that has made digital transformation so difficult.

Practical impact: By utilizing agentic AI for infrastructure modernization, organizations can overcome the traditional barriers of cost, time, and complexity that have forced many to maintain outdated systems.

• The approach enables companies to reduce operational bottlenecks while creating more agile and responsive organizational capabilities.
• The platform is increasingly being applied not just to legacy modernization but also to refreshing current applications.