The first big project I had as a professional SWE was to rebuild a checkout page to use React. Seems like overkill for a single checkout page to be its own Reac

The first big project I had as a professional SWE was to rebuild a checkout page to use React. Seems like overkill for a single checkout page to be its own React app? It wasn’t. There was a lot of edge cases. It needed to handle different countries (some have states, some have zip codes, Brazil has a crazy tax scheme), different SKUs, different payment methods (including resellers), free trials, etc. The original template + jQuery rendered version was nearly impossible to work with. Any sort of change would take forever and would lead to bugs whose patch would only increase complexity. React substantially simplified the page, and it actually looked and performed much better since there wasn’t any jankiness from HTML rendering before JS could correctly format the page. We were then able to experiment on the page to optimize the experience and drive conversions. TL;DR, more often than you would expect, the tiny performance costs you face from using a SPA is more than made up for by being able to develop quickly and more confidently.