You don't "need" to do any of that on the back-end either to launch a product. Not sure what distinction between FE and BE you think there is here. One messes up an application on the server, the other messes up an application on the client. And there are plenty of avenues for being a clueless plumber on the backend, like using Ruby on Rails + "gem install devise" for authn + "gem install carrierwave" when the boss tells you they want avatars, without having much idea how anything actually works.