Embracing InnerSource at EY : A Platform-centric approach

Adopting open-source ways of working within an enterprise can unlock real value—driving innovation, breaking down silos, and boosting collaboration. But scaling it across a large organization is easier said than done. You run into challenges like siloed teams, governance complexities, and cultural resistance. That’s where InnerSource comes into play.

At EY, we’ve embedded InnerSource principles into some of our core platform patterns and scaled them across the enterprise. Along the way, we’ve gathered plenty of insights, practical lessons, and success stories.

In this session, we’ll dive into:
✅ What InnerSource is, how it differs from open-source, and how it fosters transparency, shared ownership, and cross-team collaboration
✅ Lessons from our InnerSource journey at EY—what’s worked, what hasn’t, and how we’re continuing to evolve
✅ Best practices for scaling InnerSource—governance models, contribution workflows, and the tools that make it all work
✅ Real-world stories and examples from both EY and other enterprises using InnerSource to drive meaningful change
✅ How to overcome common roadblocks—cultural inertia, adoption hurdles, and balancing InnerSource with business goals

As the Platform Presales Leader at EY, I’ll be sharing our perspective on how we’ve made InnerSource work—at scale, and as a core part of EY Fabric, our foundational technology platform.

InnerSource is changing how enterprises build software by bringing the spirit of open-source collaboration into internal development. It’s not just a process shift—it’s a cultural one. Here’s what it actually enables in practice:

1. Tear Down Silos
   When teams contribute to each other’s code, knowledge flows more freely and duplicated work drops significantly.

2. Move Faster Without Sacrificing Quality
   Adopting open-source-style workflows—like code reviews and open visibility—helps speed up development while keeping standards high.

3. Build Once, Reuse Often
   Good solutions don’t need to be rebuilt every time. InnerSource makes it easier to find, use, and improve existing code across teams.

4. Encourage Real Innovation
   When developers have space to experiment and contribute beyond their immediate teams, great ideas surface more often.

5. Make Work More Engaging
   Developers get to learn from others, work on a wider variety of problems, and feel part of something bigger than their immediate backlog.

6. Get Teams Ready for External Open Source
   Working the InnerSource way helps teams build the habits and confidence they need to contribute to open source when the time comes.

7. Keep Business and Engineering Aligned
   By making code more accessible and contributions more visible, InnerSource helps drive outcomes that matter—faster delivery, better software, and happier teams.

At its heart, InnerSource is about turning internal projects into communities—where sharing, learning, and building together are the norm, not the exception.