How to reduce CloudFront request costs as SaaS grows?

The Cache-Control: immutable header only affects the browser and does not reduce requests on CloudFront. For caching to work properly, use Cache-Control: public, max-age=31536000, immutable with versioned file names — for example, app.v1.js. This way, CloudFront can store the content for up to one year and avoid repeated requests. Without this setup, CloudFront will continue receiving and counting every request, even if the content hasn't changed.

There are several effective strategies to reduce CloudFront request costs as your SaaS grows:

1. Optimize caching: Implement proper caching strategies by configuring appropriate Cache-Control and Expires HTTP headers on your objects. Use longer max-age values where possible, and consider using the 'immutable' directive for static assets that don't change. This can increase your cache hit ratio and reduce the number of requests to your origin server.

2. Leverage CloudFront Origin Shield: This feature provides an additional caching layer that can help reduce the load on your origin server and potentially lower costs for origin requests.

3. Use CloudFront Functions: These allow you to perform lightweight processing at the edge, which can reduce origin server load and improve response times, potentially leading to fewer overall requests.

4. Implement Service Workers: While not directly related to CloudFront, implementing Service Workers on the client-side can indeed help reduce the number of requests for static assets by caching them locally in the user's browser.

5. Optimize your application: Review your application code to ensure you're not making unnecessary requests. Combine and minify CSS and JavaScript files to reduce the number of individual file requests.

6. Use CloudFront price classes: If your audience is concentrated in specific geographic regions, you can use price classes to exclude more expensive edge locations. This can significantly reduce delivery costs while still serving your target audience effectively.

7. Monitor and analyze usage: Regularly review CloudFront usage reports to identify optimization opportunities and track metrics like requests and data transfer.

8. Consider using compression: Enable CloudFront's compressed data caching capabilities. This can reduce data transfer costs by serving compressed objects to compatible client browsers.

9. Implement geographic restrictions: Use CloudFront's geographic restriction feature to limit content delivery to specific regions if applicable, potentially reducing unwanted traffic and associated costs.

10. Secure against abuse: Implement AWS WAF rules to protect your CloudFront distributions from bots or unwanted traffic that could inflate your costs.

Remember, while these strategies can help reduce costs, it's important to balance cost optimization with maintaining high performance for your users. Regularly monitor your application's performance metrics alongside cost metrics to ensure you're striking the right balance.

Sources
Question regarding with CloudFront for content delivery | AWS re:Post
Increase the proportion of requests that are served directly from the CloudFront caches (cache hit ratio) - Amazon CloudFront
Cost optimization - Amazon CloudFront for Media

Try these strategies:

1 --> Cache Header Adjustments: Configure Cache-Control with long max-age values (e.g., max-age=31536000) and use immutable for static files that don’t change.

2 --> File Versioning: Use URL versioning (e.g., app.js?v=1.2) to avoid cache misses for updated files.

3 --> Service Workers: Implement Service Workers for local asset caching in the browser, reducing the need for CloudFront requests.

4 --> CloudFront Caching Policies and Monitoring: Adjust cache policies and set up CloudWatch alerts to identify spikes and optimize caching behavior.