If you use any third party product that uses the Microsoft account for logging in, it's an educational experience to just have the network tab open when you log

If you use any third party product that uses the Microsoft account for logging in, it's an educational experience to just have the network tab open when you log in and count the distinct, Microsoft-owned domains that the login process will cycle you through. There are companies that keep their products' infrastructure in separate siloes; there are companies that manage to merge everything into a unified architecture - and apparently there is Microsoft, that makes sure each of its products has to talk with every single one of its other products to get anything done.