Automation-First Post-Merger IT Integration: From ERP Migration Challenges to AI-Driven Governance and Multi-Cloud Orchestration

Post-merger integration (PMI) remains one of the most challenging aspects of mergers and acquisitions. While financial and strategic objectives dominate public announcements, it is the integration of IT systems—ERP platforms, HR applications, customer management, and data infrastructures—that often determines success or failure. Historical evidence shows that IT mismatches can delay synergy realization, inflate costs, and even derail mergers altogether. Until the mid-2010s, PMI processes were largely manual, dependent on siloed IT teams, bespoke scripts, and protracted ERP harmonization projects. This often resulted in multi-year integration timelines and recurring risks of disruption. By 2025, however, advances in automation, DevOps, integration platforms as a service (iPaaS), observability frameworks, and generative AI (GenAI) have transformed PMI into a structured, programmable process. Today, automation-first strategies enable IT leaders to consolidate infrastructures, migrate workloads, and enforce governance with reduced reliance on manual oversight. This paper reviews the evolution of PMI strategies from 2010 to 2025, highlights automation-driven blueprints, presents emerging GenAI and agentic AI applications, and examines challenges and future trajectories.