Based on our record, Kuzzle seems to be more popular. It has been mentiond 2 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.
You can try https://kuzzle.io/, the platform is a highly scalable Node.js application and include it's own realtime engine in C++. Source: almost 2 years ago
Also I recommend you to use foreign-key database structure, instead of documents. To my opinion it suits better to Parse Server. If you wanna use documents, you could try kuzzle also good solution! Source: about 3 years ago
Braze - Braze is an engagement platform that empowers growth by helping marketing teams to build customer loyalty through mobile, omni channel customer experiences.
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
AWeber - AWeber is an Email marketing software that's easy to use. Send email newsletters & autoresponders and deliver top notch emails.
Back4App - Low code backend to build apps faster and scale easily.
Optimizely - A/B testing you'll actually use.
Parse - Build applications faster with object and file storage, user authentication, push notifications, dashboard and more out of the box.