FrontendTable-stakesAround since 2011
Bootstrap
A popular CSS framework of ready-made layouts, buttons, forms and grids that lets developers build a decent-looking, responsive site quickly without designing everything from scratch.
Think of it like
Flat-pack furniture: quick to assemble and perfectly usable, but every flat ends up looking a bit like every other flat.
Junior or senior?
Table-stakes, and common in internal tools and admin panels.
Senior sounds like
Can say when they customised or outgrew it, and may compare it with Tailwind.
Ask them
“How did you make a Bootstrap site look like your company's own design rather than stock Bootstrap?”