While not strictly build vs buy (eg: technically you still have to "build" a postgres cluster and in house expertise even when buying AWS Aurora) but I generall

While not strictly build vs buy (eg: technically you still have to "build" a postgres cluster and in house expertise even when buying AWS Aurora) but I generally like the ideas in the classic https://mcfunley.com/choose-boring-technology https://mcfunley.com/choose-boring-technology IMO your product is the only thing you build, as much as possible should buy everything else. There is eventually an inflection point where your product is so mature that the opportunity cost of improving it operationally vs marginal next feature you will eventually save money, but that scale has been growing YoY for a while (AWS mostly gets cheaper every generation so far) .