HTTP/2 is a major revision of HTTP protocol and tries to solve some of the limitations of HTTP 1.1, increasing performance and security.
OAuth2 is an open-standard authorization protocol that provides applications the ability for secure access.
Amazon SQS is a fully managed message queues for microservices, distributed systems, and serverless applications.
Google Cloud PubSub provides messaging between applications and is designed to provide reliable, many-to-many, asynchronous messaging between applications.
The Google Calendar API lets you integrate your app with Google Calendar, creating new ways for you to engage your users.