Abstract
What does it take to successfully modernize and migrate a mission-critical line of business running on a 40-year-old monolith to a more modern SaaS? In this talk, I'll share my journey of leading a large media organization to evolve a deeply embedded legacy system into a modern, service-oriented SaaS platform. To be clear, this wasn't a clean-slate rewrite—it was a careful transformation that involved unpacking decades of tribal knowledge, understanding complex business rules, and reshaping existing workflows while creating new ones. Dealing with tight integrations with other parts of the systems in the organization, all the while maintaining business continuity for the different lines of business that still run on the monolith. No migration is complete without a successful decommissioning, yet it must be done without risking revenue and business as usual.
We'll explore how domain-driven design and systems thinking guided us through complex decision-making, from identifying bounded contexts to decoupling capabilities. I'll discuss some of the architecture patterns that worked—and the ones that didn't—along with the lessons learned in stakeholder and team alignment, delivery, and balancing pragmatism with long-term goals. Whether you're staring down a legacy system or already in the trenches of migration, I'll share my hard-won insights to help you lead change with clarity and resilience.
Spoiler Alert: It's not just about the components, services, and architecture that will result in a successful modernization of systems. Systems are for people. Understanding the socio-technical challenges of an extensive modernization is the key.
Speaker
Indu Alagarsamy
Principal Engineer @CircleCI, 25 Years of Software Development Experience
Over the past 25 years, Indu has worked across various industries, including publishing and media, healthcare, finance, biotech, and emergency services. She helped lead and successfully deliver a complex legacy modernization initiative for the NYTimes. She is currently working as a Principal Engineer at CircleCI to help improve the overall developer experience by enhancing CI/CD capabilities and enabling faster, more reliable software delivery.
She loves making sense of complex systems. She leans heavily on Domain-Driven Design and Systems Thinking to unpack complexity in a structured manner—but also borrows freely from Design and other disciplines, to shape unique approaches for understanding and solving problems. It's a bit of a remix, but it works. She writes about what she learns (and sometimes what she unlearns) at domainanalysis.io.
