I am usually in charge of the front-end-part of the projects we do. It's e-commerce-websites done with Hybris mostly, so I'm pretty free to pick an approach.
We usually need CSS, JS, Icons and static templates for prototyping.
For CSS I would stick to SASS with auto-prefixing and uglifying by PostCSS. I went with PostCSS-only for a former project, but I wouldn't again—SASS is just so much simpler to handle and set up.
For JS it's usually ES6-Syntax with modules in their own files. There's a global event-handler for cross-module-communication and if state is needed it's stored in data-attributes in the DOM. I probably wouldn't need jQuery for new projects, but some Out-of-the-box-Hybris-Stuff still needs it so we might as well leverage it where it makes sense (getting DOM-Nodes out of HTML-Strings mostly).
For icons I tried Sprites, Icon-Fonts, Grunticons, but nothing beats inserting SVG into the DOM. Never doing it differently again. (Until something better shows up!)
For HTML-Templates I try to pick the simplest to set up, which has been Assemble.io for the last projects. I hope to find something quicker and simpler, though. I might use Hugo for the next.
This is all for server-rendered sites. I don't have prod-experience with SPAs like React/Angular/etc. yet, but I'd most likely go with Angular if I were asked forced to pick one, because it seems to be the best for hiring and prominent in the enterprise-area (as in "nobody ever got fired for picking Angular").
Personally I prefer React and use it with styled-components for the new frontend for DevLids.com. I like its functional nature and how lightweight it is.
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