Beyond The Search Engine: Improving Relevancy through Query Expansion

Taylor Rose and David Mitchell • Back to Haystack 2019

Due to a variable inventory and an ephemeral data set, users often search for terms that are outside of our corpus. This leads to empty search result sets, despite often having relevant content for our users.

In order to improve relevancy, we moved beyond the search engine and implemented a number of Query Expansion techniques, including spell correction, category identification and synonym matching.

In this talk, we will outline how we used machine learning and heuristics to improve the search experience for our users while highlighting successes and failures along the way.

Taylor Rose


Taylor is a Senior Software Engineer on the search team at Ibotta, a Denver-based online shopping rewards platform. He began his career doing full-stack generalist development for startups but took an interest in the search space at Ibotta. As the company grew, browsing content became impossible without a fully featured search engine. He's spent the last two years absorbing search knowledge and applying it to Ibotta's unique search problem.

David Mitchell


David Mitchell is a Search Engineer at Ibotta with 14 years of experience in software spanning a wide variety of industries, from building slot machines to geospatial distribution tools and now mobile shopping.

Since the early days of Elasticsearch (1.0!), he has been passionate about search and is excited about building a world class search experience at Ibotta.