From the perspective of the “engineer”’s responses, I’m guessing by this is a VERY senior engineer, maybe a technical fellow or whatever Facebook calls them.
Also possible that he pinged a random junior engineer for a fresh perspective. Social media trends tend to start with a younger audience. However the engineers’s comment on team assets implies seniority.
Yeah, like just below the CTO or whoever probably. Even then they just quickly switch to just kinda bouncing the whatever Zuck comes up with back at them.