Indico - The 20 Year History and Evolution of an Open-Source Project at CERN

Explore the remarkable 20-year journey of Indico, CERN's open-source event management toolkit, in this comprehensive conference talk from EuroPython 2025. Discover how this powerful platform, which has hosted major conferences including EuroPython itself in 2006 and 2007, has continuously evolved while serving thousands of events at CERN and other major international organizations. Learn about the unique challenges of maintaining a long-lived web application, including strategies for managing technical debt, adopting new technologies, and serving a continuously growing user base without disruption. Follow the project's fascinating technical evolution from its origins as a PHP/MySQL application through its transitions to mod_python with ZODB, a custom WSGI implementation, and ultimately to a modern Flask/Postgres/React architecture. Gain valuable insights into real-world architectural decisions for open-source projects and understand the delicate balancing act required to integrate new technologies while managing legacy code. Benefit from the experiences of two team members who share practical strategies for keeping systems current with emerging technologies while maintaining stability and functionality for existing users.