Your AWS bill shows unexpectedly high data transfer costs due to inter-region traffic and public internet access. How would you optimize AWS data transfer costs?

To optimize your AWS data transfer costs, I would recommend the following steps:

1. Analyze your network usage: Use AWS Cost Explorer and CloudWatch to understand where your data transfer costs are coming from. Look for patterns in inter-region traffic and public internet access.

2. Minimize inter-region data transfer: Avoid transferring data between AWS regions unless absolutely necessary. Try to keep related resources in the same region where possible.

3. Use Amazon CloudFront: Implement CloudFront as a content delivery network to cache frequently accessed content at edge locations. This can significantly reduce data transfer from your origin servers to end users.

4. Implement VPC endpoints: Use VPC endpoints to keep traffic between AWS services on the private AWS network instead of going over the public internet. This can reduce data transfer costs, especially for services like S3 and DynamoDB.

5. Consider AWS Direct Connect: For consistent, high-volume data transfer between your on-premises network and AWS, Direct Connect can be more cost-effective than transferring data over the public internet.

6. Optimize S3 access: If you're using S3 heavily, consider using S3 Transfer Acceleration for faster uploads from distributed locations. Also, implement proper S3 storage classes and lifecycle policies to reduce storage and retrieval costs.

7. Compress data: Where possible, compress data before transfer to reduce the volume of data being moved.

8. Monitor and adjust: Continuously monitor your data transfer patterns using AWS tools and adjust your architecture as needed. Look for opportunities to cache data, reduce redundant transfers, or optimize application-level data access patterns.

By implementing these strategies, you should be able to significantly reduce your AWS data transfer costs while maintaining performance and availability for your applications.
Sources
COST08-BP02 Select components to optimize data transfer cost - Cost Optimization Pillar
COST08-BP03 Implement services to reduce data transfer costs - AWS Well-Architected Framework (2022-03-31)
ELB internet transfer cost | AWS re:Post

Hey there - I would recommend taking a look at the following resources for recommendations:

https://aws.amazon.com/blogs/architecture/overview-of-data-transfer-costs-for-common-architectures/

https://catalog.workshops.aws/awscff/en-US/playbooks/networking/datatransfer

https://docs.aws.amazon.com/cur/latest/userguide/cur-data-transfers-charges.html

https://www.youtube.com/watch?v=FP1OgyeMMgs

There is also a data transfer dashboard you can configure for better visibility: https://www.wellarchitectedlabs.com/cloud-intelligence-dashboards/