Even though we may have decided to build the app using Web technologies, our technology decisions aren't done. Something that would be helpful to have an understanding of early on is how much to rely on backend processes and how much to do in the front end.
In the case of Sweater, we could design the app to be almost completely backend driven. But it's hard to make a good case for this. Having the backend get weather data for the current user (making sure you keep track of the current user's location), compose a page, send that back to the client, and then design a mechanism that periodically refreshes the page makes little sense when the client can do it all in the front-end and do it with grace.
So, it looks like Sweater will be a relatively simple full-on SPA.
We still need to consider what kinds of front-end libraries or frameworks we might leverage for the overall app structure (e.g., Vue.js. React, Angular) as well as the UI/UX (e.g., Bootstrap, Materialize). Whether we use a UI/UX framework will depend a lot on what the potentially evolving design for the app specifies. This in turn could also influence the selection of core technology used for the app structure.
But for the hell of it, let's start by looking at what happens with just a Plain-old Web tech implementation.