Velocity = all about performance <a href="http://velocityconf.com/velocity2014/public/schedule/grid/public" rel="nofollow">http://velocityconf.com/velocity2014/public/schedule/grid/pu...</a><p><a href="http://www.apachecon.com/" rel="nofollow">http://www.apachecon.com/</a> which is 50% about search (Lucene, Solr etc) and big data these days<p>I'm keeping an eye on QCon (<a href="http://qconlondon.com/schedule" rel="nofollow">http://qconlondon.com/schedule</a>) but found it kind of expensive.