I think many good search engines already exist: CloudSearch, Elastic Search, Lucene, even Google Site Search. Often the difficulty with search is not the engin

I think many good search engines already exist: CloudSearch, Elastic Search, Lucene, even Google Site Search. Often the difficulty with search is not the engine but rather deciding what to put in it - what documents? What fields are searchable? Which fields are facets? What to use as a list for synonyms? How to handle stemming?How to support multiple languages etc. Those configurations can make a world of difference in the quality of a user's search results.