This solution is generated by ChatGPT, correctness is not guaranteed.

AI solution for System Design on BFE.dev
6. Design a Typeahead Widget

When designing a Typeahead widget, there are a few key factors to consider, including:

  1. UI Performance: The widget should provide quick and responsive suggestions as the user types, without causing any lag or delays. This can be achieved by optimizing the code and minimizing network requests.

  2. API Performance: The widget should retrieve suggestions from the server as quickly as possible, to avoid any delays or timeouts. This can be achieved by leveraging CDN's and using server-side caching techniques.

  3. Caching: The widget should cache frequently-used data locally, to speed up performance and reduce the number of network requests. This can be achieved using browser cache or local storage.

  4. Modularization: The widget should be modular and easy to integrate with various systems or frameworks. This can be achieved by using a well-defined API, and breaking the code into reusable and maintainable components.

  5. Animation & Timing: The widget should provide a smooth and visually-engaging UX, including animations and transitions for the suggestion layer. This can be achieved using CSS animations or JavaScript libraries.

To estimate data size, we should consider the number of suggestions returned per query, the length of the suggestions, and the frequency of queries. It's important to strike a balance between providing enough data to be helpful, but not so much that it slows down the widget or becomes overwhelming for the user.

Overall, designing a Typeahead widget requires careful consideration of multiple factors - UI and API performance, caching, modularization, and animation - as well as careful estimation of data size and frequency of queries.