Soulmate is an Redis-based open source project designed to help developers build faster autocomplete features. According to the project's ReadMe "It uses Redis's sorted sets to build an index of partially completed words and the corresponding top matching items, and provides a simple sinatra app to query them."

Soulmate was developed by the ticket searching company SeatGeek. You can see it in action on the company's site.

More from the ReadMe:

  • Provide suggestions for multiple types of items in a single query (at SeatGeek we're autocompleting for performers, events, and venues)
  • Results are ordered by a user-specified score
  • Arbitrary metadata for each item (at SeatGeek we're storing both a url and a subtitle)