App Engine isn’t Google’s only serverless product. Google also has three others: Cloud Functions, Cloud Run, and Cloud Run for Anthos. Cloud Run operates on event-driven code. Instead of App Engine, something has to trigger them. You can think of Cloud Functions as the glue between the various services, whether they’re on Google Cloud or third party. It scales automatically and is extremely low cost— Google bills you for execution time to the nearest 100 ms.