Build a highly reliable, cost-effective web application with a few public APIs, low baseline traffic and occasional spikes, using Cloud Load Balancing. Where do you host static content and APIs, and what database do you use?

This solution is cost-effective and scales well for low baseline traffic with occasional spikes. Cloud Storage is ideal for hosting static content due to its low cost, high availability, and global reach. Cloud Functions provide a serverless, pay-per-execution model for APIs, automatically scaling to handle traffic spikes without managing servers. Firestore is a NoSQL document database that offers flexible schema, automatic scaling, and real-time synchronization, making it suitable for dynamic web applications with varying data access patterns. Other options are less optimal: Cloud CDN is for caching, not primary hosting. App Engine and Cloud SQL can be more expensive for low traffic. GKE is overkill for "a few public APIs" and "low baseline traffic," incurring higher operational overhead and cost. Cloud Spanner is a relational database designed for massive scale and global consistency, which is likely over-provisioned and more expensive for this use case. Cloud CDN is for caching, not primary hosting. Cloud Run is a good serverless option, but Cloud Functions are often more cost-effective for event-driven, short-lived API calls.