David Smiley is a well recognized Apache Lucene/Solr expert. He wrote the first book on Solr (currently in 3rd edition), he's a Lucene/Solr committer and PMC member that improves Lucene and Solr, he speaks at conferences about it, he does training, and he offers part time independent consulting services / development. Much of Lucene's spatial-extra's module was developed by David.