Cybersecurity incidents in large, distributed IT environments pose unique challenges due to their scale and complexity. This paper presents a comprehensive framework for rapid incident response (IR) and digital forensics at the enterprise scale, drawing upon industry best practices and illustrative case studies. We discuss how Security Orchestration, Automation, and Response (SOAR) platforms, along with automated play- books, can drastically reduce response times while maintaining consistency. We examine new techniques for scalable digital forensics, including distributed evidence collection and big-data analysis tools, enabling investigators to handle thousands of endpoints in parallel. We also underscore the importance of well- coordinated incident response teams with clearly defined roles and communication workflows. Key contributions include: iden- tifying challenges in large-scale IR and transforming them into opportunities for improvement; demonstrating the integration of automation and orchestration to contain threats swiftly across complex environments; highlighting innovations in forensic data collection and timeline analysis that overcome traditional tool limitations; and providing best practices for structuring incident response teams and processes to ensure a unified, effective reaction to major cyber incidents.