Every front-end project involves some automation to build it, test it, lint it, run dev servers, measure bundle size, and what not. npm scripts are fine for one-liners, but as the workflows grow more complex — run these things in parallel, then do something else, but only if building for production — you need a more coherent orchestration solution. In many projects, this means bash — it can handle anything, from the trivial && to if .. fi mostrosities in separate shell scripts.
