Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
Dynamic Yield - Personalization & customer experience management
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
Lytics - Lytics is a company that utilizes machine learning to collect and analyze data to help you find new approaches to marketing. They offer unique and customized experiences to each customer. Read more about Lytics.
Klevu - Klevu offers instant site search solution for eCommerce stores.
BloomReach - Get people to your products faster. Personalize your customer experience. Increase your revenue.