Speaker: Tomáš Ehrlich (twitter) initiated PyCon CZ and is a translation manager for Django Girls
React is a library, not a framework, for user interfaces, and thus is basically the view/frontend/presentation logic/template engine, it renders data and handles events. React's main feature is only rendering diffs on changes, not re-rendering the entire DOM, because DOM operations are expensive.
React with Django
You could just use React in Django as a frontend library, and integrate it with existing projects, but it's not DRY, you'd re-write lots of stuff.
Instead you could use full-stack react (server-side), replacing views and templates, and use Django only to provide Business Logic, Authentication, Form Validation and Admin Functionality via REST APIs.