I would like to draw your attention to the recent documentation updates, because as you know, not only product features themselves are valuable, but also good documentation that details how to use them in practice, improving your skill set and making you more productive.

Concerning XPO, I suggest you checking this link as it will make you more fluent in using the ORM Data Model Wizard, OData and other design time features:

As for XAF, check out this update to learn about new elements which you might have not used in the past:

If you want to improve your mastery for other DevExpress products, check out the full list of recent documentation updates here.

We constantly update our documentation and examples, so do not forget to check the What's New documents from time to time, because it lists more than new product features and fixed bugs.