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.
MikMak - Infomercials that aren't boring and are on your phone!
ElasticSearch - Elasticsearch is an open source, distributed, RESTful search engine.
Clerk - Clerk.io, the artificial intelligence for e-commerce that knows your customers interests.
Klevu - Klevu offers instant site search solution for eCommerce stores.
Netsuite SuiteCommerce - NetSuite SuiteCommerce enables B2C and B2B businesses to manage customer interactions through a cloud eCommerce platform.