Internal technical communities have become a cornerstone of how Bloomberg fosters engineering excellence, cross-team collaboration, and sustained innovation. These grassroots groups shape best practices, address shared challenges, and enable engineers to develop beyond their daily roles, directly influencing the company’s technological growth and culture.

In this talk, we’ll explore one of our firm's most established internal communities: Bloomberg's Python Guild. Active for more than a decade, the Guild has grown into a thriving, organisation-wide network supporting thousands of Python developers. It not only advances internal excellence but also actively contributes to the broader Python ecosystem through open source projects, sponsorship of major conferences, and collaboration with nonprofit organisations.

We'll share practical insights into how such internal communities are structured, discuss their measurable impact, and provide guidance on building and sustaining communities that drive meaningful innovation.

Whether you're thinking about starting an internal community in your company or looking for fresh ideas to nurture and expand an existing one, this talk will provide plenty of inspiration and guidance.