Twitter is a mid sized tech company though, with a mere 5,500 employees. Facebook and Google are an order of magnitude bigger, and half the size of Uber and Netflix. It’s also a tiny bit smaller than Doordash and AirBnB by comparison.
I guess that depends on the definition of mid sized company. I don't know if there is a fundamentally different/better definition, but Gartner defines a mid sized company to have up to 999 employees and $1 billion of annual revenue [1]. Twitter has way more employees and revenue than that.
[1]: https://www.gartner.com/en/information-technology/glossary/s...