I can't speak to the technical aspects here (I'm only familiar with nextjs not rails, so it's unclear to me how much of the article is just a reflection of the author's own comfortability with rails or a reflection of a more technically suitable architecture). But I do find it really weird that a company which apparently has multiple software engineers is worried about infrastructure costs amounting to less than $1k a month... Seems penny-wise pound-foolish to be worried about hosting bills.