Isn’t twitter a pretty simple thing… db with writes and reads… it was maybe still is rails? I don’t know MySQL , Pgsql have come a long way and most of the hard parts would be scaling these services…. Keeping good caches in memory with redis or memcached… not really sure I see twitter being all that crazy other then it being so many people and so many years of edge case handling they would be hard for an outsider to follow … but it’s not like it was handling a complex UI or enterprise style hacks for a handful of worth it customers…

Would be really interesting to see the code base for sure and definitely exciting to modify a code base handling so much traffic… not sure I can recall a fail whale in many years so maybe they did something right or maybe fearing the whale set the large organization into stone code fear

Contrast that with Tesla and ever car is requesting data from Tesla servers and many many different complex interactions with much more complex engineering to accomplish a task and id imagine the Tesla engineering to be pretty impressive… but who knows it probably does not handle the same amount of read or write traffic…