ApacheCon Europe 2012

Rhein-Neckar-Arena, Sinsheim, Germany

5–8 November 2012

Personalized Search on the Largest Flash Sale Site in America

Adrian Trenaman

Audience level:
Lucene, Solr & Friends

Wednesday 3:45 p.m.–4:30 p.m. in Level 1 Right


This talk provides a tour of how Apache Solr is used to power search for America's largest flash sale site, www.gilt.com. We show how to address the challenges of providing listings for fast moving inventory in a search space personalized for each of our members. The solution, built on Play Framework comprises less than 4,000 lines of code, and provides response times of 40ms on average.


Gilt Groupe (http://www.gilt.com) is an innovative online shopping destination offering its members special access to the most inspiring merchandise, culinary offerings, and experiences every day, many at insider prices. Every day new merchandising is offered for sale at discounts of up to 70%. Sales start at 12 noon EST resulting in an avalanche of hits to the site, so delivering a rich user experience requires substantial technical innovation.

Implementing search for a flash-sales business, where inventory is limited and changes rapidly as our sales go live to a stampede of members every noon, poses a number of technical challenges. For example, with small numbers of fast moving inventory we want to be sure that search results reflect those products we still have available for sale. Also, personalizing search – where search listings may contain exclusive items that are available only to certain users – was also a big challenge

Gilt has built out keyword search using Scala, Play Framework and Apache Solr / Lucene. The solution, which involves less than 4,000 lines of code, comfortably provides search results to members in under 40ms. In this talk, we'll give a tour of the logical and physical architecture of the solution, the approach to schema definition for the search index, and how we use custom filters to perform personalization and enforce product availability windows. We'll discuss lessons learnt, and describe how we plan to adopt Solr to power sale, brand, category and search listings throughout all of Gilt's estate.