The post mentions a few: Dropwizard for RESTful APIs (http://www.dropwizard.io which includes a bunch of good libraries), Guava, Guice, Hysterix, etc. We use Kafka for stream processing, Hadoop for batch processing.
SQL is just one type of DB language we use, but yes we use JDBI with some extensions we've built (such as https://github.com/HubSpot/Rosetta and other non-opensource) for our SQL database of choice, MySQL.
But we also use a number of other databases with native java clients, such as HBase and ElasticSearch.
