Unlocking productivity.

A software platform's greatest source of competitive advantage isn't the product it ships — it's the speed at which it can ship it. Feature velocity, code quality, and engineer satisfaction all compound over time. So does their absence.

As a product lead on the Windows Platform team, I identified that our engineers were falling behind — not because of skill or effort, but because of the system underneath them.

Insight

The past was slowing down the future.

The Windows OS is among the most complex pieces of software ever built. Thirty years of accumulated legacy code, spread across millions of files, written across generations of programming languages. Each build is a distributed orchestration across hundreds of machines — tens of thousands of individual tasks, any one of which can invalidate the entire run. Supporting thousands of engineers across hundreds of branches daily, the system produces more than 2 petabytes of storage artifacts and telemetry every single day.

The consequence of that complexity was time. Windows engineers waited up to 20 hours for build validation — every day — before they could know whether their changes held.

I partnered with an internal Microsoft Research team to study what that wait was actually costing. The findings were unambiguous: low system efficiency was directly depressing both productivity and satisfaction. The hypothesis followed naturally — compress the build, and you don't just save time. You unlock a different kind of work.

Idea

Only rebuild what changed.

The legacy orchestration tool at the heart of our build system was, like the OS itself, approximately 30 years old. Replacing it was not a small decision. It required mapping dependencies across organizations, building alignment across teams with competing priorities, and translating a technically complex migration strategy into a roadmap that engineering leadership could fund and execute against.

I identified pilot customers based on their configuration profiles and code volume — choosing partners whose success would validate the approach for the broader population. I led monthly development sprints, gave keynote presentations at internal developer conferences, and owned the go-to-market strategy to drive adoption at scale.

The replacement technology was BuildXL: an open-source distributed build engine that caches intermediate artifacts across runs. Instead of re-executing all 600,000+ build tasks from scratch, BuildXL identifies precisely what has changed and rebuilds only that — pulling everything else from cache. The build becomes, for the first time, a function of what's new rather than a repetition of everything that came before.

Impact

10 hours returned. Every day.

We scaled BuildXL to the full Windows engineering organization. Build time fell from 20 hours to 8. Eleven additional hours of productive developer time — unlocked, daily, across thousands of engineers. No more waiting idly for validation and lower context switching. I prioritized customer onboarding by ranking branch families by total PR volume, ensuring the majority of product changes were validated sooner.

The downstream effects were measurable across every dimension that matters: platform reliability rose, feature velocity increased, and developer satisfaction followed.

Platform reliability rose from 30% → 87%. PR volume increased 23.5% per week. Developer satisfaction (measured by NSAT) rose from 102 → 124.

Thirty years of accumulated constraint, systematically unwound. Not by replacing what engineers built — but by freeing them from the time it took to build it.