How Expedia.com was built on machine learning

Expedia has grown far beyond a search engine for flights -- it's now the parent company of a dozen travel brands including Trivago and Hotels.com The business of delivering quality flight search results is tough, and Fleischman describes it as an "unbounded computer science problem". The reason for this is because flight itineraries and schedules are constantly changing, and Expedia's proprietary'best fare search' (BFS) has to'learn' and adapt all the time. The extent of the problem can be summed up by one statistic. In those three seconds you will see, on average, 16,000 flight options, in order of convenience or price or time.