Legacy systems often limit performance and scalability. This session explores how Rutul Desai modernized a high-traffic iOS app using reactive architecture, analytics, and automation. Learn how to migrate to reactive systems, implement data-driven monitoring, and integrate testing at scale. Attendees will gain practical tools to improve app reliability, user experience, and business outcomes. Ideal for mobile engineers and tech leads. Key Takeaways: • Learn how to transition from legacy iOS architectures to modern reactive patterns using Combine and SwiftUI. • Discover how to implement scalable analytics and monitoring tools like OneTag and New Relic for actionable insights. • Understand best practices for automated unit and UI testing to ensure robust delivery pipelines. • Explore strategies for optimizing performance and reliability in large-scale enterprise mobile apps.