Comment by mtejo

twitter runs its own datacenters and has teams to support that. Since its not in a cloud the company runs all their own internal platform stuff you would get on something like aws. that is a large engineering effort. theres also the andorid and ios app, more teams. elon tweeted out a picture for tweet or timeline reads i think. each square is basically a team with an oncall rotation. this is off the top of my head, there's plenty more not visible stuff happening