There was a post here by the head of the team about 4 years ago going over his thoughts on the matter https://news.ycombinator.com/item?id=7364465 https://news.

There was a post here by the head of the team about 4 years ago going over his thoughts on the matter https://news.ycombinator.com/item?id=7364465 https://news.ycombinator.com/item?id=7364465 and as someone else mentioned the After Action Report summarized the bullet points well: https://wiki.mozilla.org/Identity/Persona_AAR https://wiki.mozilla.org/Identity/Persona_AAR