How about scaling? If you find something has already been done, then why not try making it bigger and better - yeah there&#x27;s a library that can crawl a webpage, but how about crawling every webpage?<p>Yeah there&#x27;s a library to recognise faces, but what about building a very quick search engine on top of it? What about one that can automatically spot celebs?<p>Yeah there&#x27;s a library that can do substring matching using clever algorithms, but can you make it work in parallel across a cluster, can you achieve linear speedups?<p>Pick something that you find cool, then make it 1000 times bigger! :D