I worked for Twitter up until 2017 and when I was there it was much higher than 20-30%, definitely >50%. It's very possibly changed since then, but at least at

I worked for Twitter up until 2017 and when I was there it was much higher than 20-30%, definitely >50%. It's very possibly changed since then, but at least at that point in time Twitter was running Mesos on many thousands of machines.