I still do not understand why twitter needs one. Fire everyone, bring on a skeleton crew of engineers to fix bugs, and maybe 4 product engineers, a couple managers and a couple designers. Boom, instantly ultra profitable.
You would need quite a few engineers just to handle tweaks requested by legal and CS. Just a few engineers to handle the mature (ie probably spaghetti) ecosphere of systems in their architecture is never going to scale. Nor to just stop it falling apart, never mind progressing any new features.
From their talks about their architecture, their massive "Source" repository etc its sounds like they had 1000s of commits per day across hundreds of systems. Ie like many larger companies. To keep up that velocity would need a lot of developers and overhead staff. Even if they cut away "nice to have" systems, sunset a lot of apps and projects, and focused only on a lean core that would still be a huge architecture, which needs X amounts of staff to maintain and progress. What X is a I don't know. Maybe 50, maybe 200, maybe 1000.
You're leaving money on the table with zero sales staff.