What interesting features have you implemented at your last job?

At my last job, I implemented interactive data visualization using React and D3.js. This allowed users to dynamically filter and analyze large volumes of information directly in the browser, without reloading the page.

I also introduced a lazy loading system for components, which significantly sped up the application's load time and improved user experience. For example, I used React.lazy and Suspense for code splitting.

const LazyComponent = React.lazy(() => import('./HeavyComponent'));

function App() {
  return (
    <React.Suspense fallback={<div>Loading...</div>}>
      <LazyComponent />
    </React.Suspense>
  );
}

Additionally, I optimized form handling by using the Formik library with Yup for validation, which simplified support and extension of forms.