Let me say it again: the only language I know is en, my browser's language is en, so en is set for me at app load time. Good. I select a new topic (which I'm interested in), and suddenly, because that topic's data is available in en, the entire web interface changes to de. I'm lost. What bothers me if that we change the interface language just because we don't have the data for the target language. Instead, the services should work in best effort mode, and return the data in the default language if the data is not available in the requested language, but the interface language shouldn't change unless the user explicitely requests it.