What are some alternatives?
When comparing simperium and Google Cloud Functions, you can also consider the following products
GUN - Self-hosted Firebase.
Google App Engine - A powerful platform to build web and mobile apps that scale automatically.
Firebase - Firebase is a cloud service designed to power real-time, collaborative applications for mobile and web.
Dokku - Docker powered mini-Heroku in around 100 lines of Bash
Pusher - Pusher is a hosted API for quickly, easily and securely adding scalable realtime functionality via WebSockets to web and mobile apps.
Azure Web Apps - Create and deploy mission critical Web apps that scale with your business