About Guy

Hi, I'm Guy.

If you run ads in a mobile app, you've probably seen things that don't quite make sense.

CPMs fluctuate without a clear reason. A major SDK suddenly slows down. Fill rate or viewability drops even though nothing changed. You might get IVT complaints from demand partners, or wonder whether your setup is actually working as well as it could. And at some point, you start asking bigger questions: what's the right mediation for me, what should my stack look like, and does adding more demand really help?

I've spent the last 15+ years on the publisher side trying to answer those exact questions.

In recent years, I ran ad monetization for a portfolio of mobile apps at Unity, working across the full stack: mediation, Google Ad Manager, SDK networks, bidders, and programmatic demand.

A big part of that work was testing. Hundreds of tests over time, on floors, auction dynamics, demand combinations, and different mediation setups. Not just to improve CPM or fill, but to understand what actually drives revenue without hurting user experience.

Being close to the mediation development teams also made a difference. I wasn't just using the tools. I had visibility into how they were built, how decisions were made, and how demand actually flows through the system.

Along the way I built Beamflow, a supply chain intelligence tool that mapped ads.txt and sellers.json data to show who was actually buying inventory and how demand was structured. The product is on pause right now, but building it taught me more about the supply chain than any dashboard ever did.

Over time, you start to see patterns. Two apps with similar setups can perform very differently, and the difference usually comes down to context: users, geos, session behavior, and how the stack is put together.

That's why I focus less on "best practices" and more on understanding what's actually happening in each case.

These days I'm back in a full-time role, and this site is where I write it all down: guides, news analysis, and free tools I built along the way.