Wagtail 0.1 came with a solid search experience, both in the admin UI and, if you need it, in the front end. We have a fall-back database backend if you don't want the hassle of a third party search service, but most of the time we recommend the default Elasticsearch backend. Since Wagtail was launched there's been an explosion of hosted Elasticsearch providers, including Amazon, Bonsai, and Elastic.co, all of whom provide the full Elasticsearch feature set via a single URL which you plug into your Wagtail settings. Wagtail 1.7 brings support for Elasticsearch 2, the default version for most of these providers. Note Elasticsearch has just jumped, confusingly, to version 5; on first glance it looks like the 2 to 5 upgrade will be much simpler than 1 to 2.