In an ideal world, there’d be all kinds of business strategy meetings, UI planning, multiple design directions considered, copy-writing and revisions, db architecting, a deep investigation into which languages to use & which dependencies serve the short- and long-term goals of the project…
But in reality, very few companies could do this. (But even they don’t.)
Instead, there’s nearly always a hodge-podge of leftover assets, unplanned forks, hasty decisions, muddled coordination, and a severe lack of funds.
Often, a “full-stack” person — maybe we used to just be called a “webmaster” — is someone who tries as hard as they can to bring all the pieces together. Sometimes extra hands hurt more than they help (see The Mythical Man-Month); sometimes you need to bring in an outside specialist (maybe because an old decision has tethered you to MVC.NET v 2.1); sometimes an absentee manager suddenly reappears to get her surprise 2¢ in at the finish line…
The more money, organization, time, and talent you have, the better. Barring any of that, it often helps for an auteur to step in, juggle 50,000 balls, and call it a website.