Why Ably integrates with functions instead of delivering them

The Ably platform supports realtime messaging applications by allowing rules to be created that invoke cloud functions such as AWS Lambdas or Google Cloud Functions. This integration with externally-managed cloud functions provides flexibility for developers and ensures minimum latency while focusing on application development rather than infrastructure engineering. By using the execution environments provided by cloud service providers, developers can benefit from reliable, performant, and scalable solutions that support a wide range of languages. The Ably solution allows function invocation after a message has been accepted on a channel, ensuring that messages are still part of the history of the source channel for potential retry or alternative business logic handling.