Learn French: Elle choisit ce pseudonyme de façon que personne ne la reconnaisse. - She chooses this pseudonym so that nobody recognizes her.

The phrase de façon que (meaning 'so that' or 'in such a way that') expresses a goal or purpose here, which requires the subjunctive mood. If it were describing a consequence that actually happened as a stated fact, it would take the indicative mood, but here it describes an intended outcome.

Why is there a ne before la reconnaisse but no pas?

The word personne is a negative indefinite pronoun meaning 'nobody' or 'no one'. When personne acts as the subject of the sentence, it pairs with ne before the verb, and the word pas must be dropped. Adding pas here would be incorrect.

Since this lesson focuses on autrui, could we use it here instead of personne?

You could technically say de façon qu'autrui ne la reconnaisse pas (so that others do not recognize her), but autrui is quite formal and typically refers to 'others' in a broad moral or legal sense. Personne (nobody) is much more natural for this situation. Notice that if you used autrui, you would need to add pas back into the sentence to make it negative!

Why does the object pronoun la come after ne rather than before it?