Bootstrap has some JS but is mostly a library of CSS classes. They built themselves a library of React components that they can use to compose UI. I've built st

Bootstrap has some JS but is mostly a library of CSS classes. They built themselves a library of React components that they can use to compose UI. I've built stuff like this using React and Vue, without any additional tooling. IMO it can be a great approach but only if there's' a cohesive agreement on the design within the company, IE it doesn't work that well when the stakeholders don't "stick with it".