Answer: Compute Engine custom machine type

## Explanation For a caching reverse proxy requiring approximately 32 GB of RAM at the lowest cost, **Compute Engine custom machine type** is the correct choice. Here's why: ### Analysis of Options: 1. **App Engine Standard**: This is a serverless platform optimized for web applications and APIs. It has memory limitations (up to 2 GB in standard environment) and is not suitable for a caching reverse proxy requiring 32 GB RAM. 2. **Cloud Run**: This is a serverless container platform that scales to zero. While it supports custom memory configurations, it's optimized for stateless containers and may not be cost-effective for a continuously running caching proxy with high memory requirements. 3. **Compute Engine custom machine type**: This is the most appropriate choice because: - Allows you to create VMs with exactly the resources you need (32 GB RAM) - Provides the most cost-effective solution for predictable workloads - Offers full control over the instance configuration - Can be optimized for memory-intensive workloads - No unnecessary overhead from serverless platforms 4. **Cloud Functions**: This is a serverless functions-as-a-service platform with strict memory limits (up to 16 GB) and is not designed for long-running processes like caching reverse proxies. ### Key Considerations: - **Memory Requirement**: 32 GB RAM eliminates App Engine Standard and Cloud Functions due to their memory limitations. - **Cost Optimization**: Compute Engine allows you to pay only for the resources you need without the overhead of serverless platforms. - **Workload Type**: A caching reverse proxy is a long-running, stateful service that benefits from dedicated resources. - **Customization**: Compute Engine custom machine types let you optimize CPU-to-memory ratio for your specific needs. ### Additional Notes: For a caching reverse proxy, you might also consider using: - **Memorystore** for Redis or Memcached if you need a managed caching service - **Cloud Load Balancing** with Cloud CDN for caching at the edge However, for the specific requirement of a caching reverse proxy with 32 GB RAM at the lowest cost, Compute Engine custom machine type is the most suitable option among those provided.

Author: Rodrigo Sales