Google App Engine Flexible Environment, part of Google Cloud Platform, is a fully managed serverless platform designed for developing and hosting web applications at scale. It offers a choice between two environments: the Standard Environment and the Flexible Environment.

Standard Environment:

• Optimized for specific languages like Python, Java, Node.js, Ruby, PHP, and Go.
• It is based on containers running on Google’s infrastructure.
• Provides features like automatic scaling, load balancing, and integration with other Google Cloud services.
• Suited for applications that need to handle heavy load and large data.

Flexible Environment:

• Allows more customization options, including custom runtimes using Dockerfiles and longer request & response timeouts.
• Based on Google Compute Engine, it automatically scales the application up and down and balances the load.
• Offers infrastructure customization, enabling the use of custom libraries, SSH for debugging, and deployment of Docker containers.
• Supports a wide array of CPU and memory configurations, enhancing performance.
• Ideal for applications that require more flexibility regarding the underlying infrastructure.

Use Cases:

1. Scalable Mobile Backends: It’s ideal for mobile applications, offering seamless integration with Firebase for an easy-to-use frontend and a scalable backend.
2. Modern Web Applications: Suitable for rapidly deploying web apps with zero-config deployments and no server management, automatically scaling to handle traffic spikes.

Benefits:

• Supports popular programming languages and allows for the use of familiar tools and frameworks.
• Handles infrastructure management, including security measures.
• Cost-effective, as it scales based on application traffic and only charges for resources when the code is running.

Key Features:

• Offers a range of language runtimes and the ability to bring any library and framework.
• Provides powerful diagnostics tools for monitoring application health and performance.

Comparison with Compute Engine:

• While Compute Engine offers more control over VMs and is ideal for customizable cloud computing, App Engine provides a higher level of abstraction, focusing more on the application and less on the infrastructure.

For a detailed exploration and understanding of Google App Engine Flexible Environment, its features, and capabilities, you can refer to K21Academy and Pluralsight. These resources offer in-depth insights and are great for anyone looking to delve deeper into what App Engine Flexible can offer.