Our client is online store for auto-parts offering huge range of auto parts. The store was based on Magento. Due to huge catalog of products the site was very slow overall. The search was also slow because it was using default Magento fulltext search.
We did a performance audit of the site and identified bottlenecks. We identified an extension which were causing performance issues in site. After fixing the extension we saw improvement in performance. We optimized mysql innodb setting to further improve performance. Replaced the default search with search based on Sphinx Search which not only helped improve performance but also improved the conversion for search.