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.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Dynamic Yield - Personalization & customer experience management
Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.
Optimizely - A/B testing you'll actually use.
Campaign Monitor - Email marketing software built for designers and their clients to run successful email campaigns.