Microsoft 365 Substrate

Quick post with my gatherings of a small research about Microsoft 365 Substrate, also known as the Office 365 Substrate.

Microsoft 365 Substrate

A brief description could be that Microsoft 365 Substrate is an "Intelligent Substrate Platform" in Office 365, applying AI to everything related with O365. Its goal is to store all the files and information (or a copy of the information) that users employ to create, collaborate, and communicate in the substrate.

It consists of storage & services to access the information. The services include Microsoft Graph, the main and preferred way of accessing the data. AI also builds insights from the substrate.

The substrate idea was initially part of Exchange's data store architecture, and in a great part relies on it. For example, all Teams substrate data goes to Exchange mailboxes (public or hidden).

365 Substrate diagram

I found the following links interesting to gather both that general idea and more details about the Substrate:

Project Cortex

Project cortex analyses content across teams and platforms, to then organize & classify it and, most importantly, build a knowledge network with the relationships between the content, the people and information extracted. Heavily uses AI, in theory not having human intervention. It is used inside the 365 Substrate.

To learn more about Cortex I found the Knowledge and Content Services Blog of interest.

Microsoft Viva

A resulting project of containing employee activity and collaboration data is clearly Microsoft Viva. You can read more about it here:


Substrate + others → MetaOS/Taos

The next logical step once you have the Substrate ready, is to join it with other pillars and try to provide richer and higher-level actions and insights. It will be a foundation over SharePoint, 365 substrate, Azure and Microsoft's machine-learning infrastructure. The specific usages of MetaOS are unknown, but a unified search across all Microsoft products represents a good example.

Further details:

Microsoft 365 Substrate published @ . Author: