That they can solve it at all is critical information. One could have expected the stack to not be able to horizontally scale this far. You are right though, th

That they can solve it at all is critical information. One could have expected the stack to not be able to horizontally scale this far. You are right though, that there is also a question of a trade-off between hosting cost on one and and the developer hours, risk, opportunity cost and lower hosting cost that come with a rewrite on the other for which one would need to know hosting cost among other critical factors.