I spent some time observing what's inside the Microsoft AI stack. Foundry, Agent Framework, Logic Apps, AI Search, Purview, Entra. After a while, I had a picture of how the pieces fit and decided to draw one myself to share.
Then recently Microsoft published AI-500, an expert certification for multi-agent systems. That made me curious whether Microsoft's view of the platform matches my own. So I plotted the certification trail against my diagram. This post shows the result.
The Microsoft AI stack as I see it
Six layers. Five of them stack vertically. The sixth runs down the side, through all the others.
Models sit at the bottom: GPT-5, Claude, Mistral, Grok, Microsoft’s own MAI and Phi, Llama, DeepSeek, and the open catalog. This is the least differentiated layer. In Foundry, swapping one model for another is a configuration change. It gets the most attention and deserves the least.
