There's definitely a performance tradeoff, one which I reference a little in the latest part and will definitely talk about more when I get to drawbacks (likely in the 5th update.) There's definitely a big class of applications where FaaS with its current limitations isn't a good choice, but I wouldn't say that class is universal.
12 factor statelessness I read as meaning more application / domain state rather than infrastructure state btw.
12 factor statelessness I read as meaning more application / domain state rather than infrastructure state btw.