Backend β€’ Jul 14, 2025

Indico: the 20 year history and evolution of an open-source project at CERN

🎀 Indico: the 20 year history and evolution of an open-source project at CERN by Dominic Hollis, Tomas Roun
πŸ”— https://ep2025.europython.eu/session/indico-the-20-year-history-and-evolution-of-an-open-source-project-at-cern

πŸ“ Abstract: Indico is a powerful open-source event management toolkit, created at the European Organization for Nuclear Research (CERN), that has been evolving over the last 20+ years. Indico has been used to host major conferences, including EuroPython itself in 2006 and 2007, as well as thousands of events at CERN, and other major international organizations/institutions alike.

Maintaining an ever-evolving project comes with unique challenges: dealing with legacy code, adopting new technologies, and managing technical debt without disrupting a large and continuously growing user base.

This talk explores the project’s technical evolution as well as focusing on how it stayed current with emerging technologies; starting as a PHP/MySQL app, it transitioned to mod_python (https://modpython.org/) with ZODB (https://zodb.org/en/latest/) , briefly used a custom WSGI implementation, and ultimately became a modern Flask/Postgres/React application - sometimes integrating multiple technologies simultaneously.

By the end of this talk, attendees will:

  • Understand the challenges of maintaining a long-lived web application.
  • Learn strategies for dealing with technical debt while keeping systems evolving.
  • Gain insights into real-world architectural decisions for open-source projects.

Join us, as two team members discuss how to stay sane with the meticulous balancing act of dealing with both technical debt and integrating new technologies/features.