Create buckets: Create S3 buckets in different regions
Configure replication rules: In the S3 console, navigate to the source bucket, select the Management tab, and then find the Replication rules. Define which objects to replicate, and specify the destination bucket and region.
Set up IAM roles: Create an AWS Identity and Access Management (IAM) role that S3 can use to replicate objects.
Enable versioning: Ensure that versioning is enabled on both the source and destination buckets.
Monitor replication: Review and monitor the replication process.

The AWS Lambda execution role grants Lambda functions permissions to access AWS resources, such as S3 or DynamoDB, and is crucial for ensuring secure and controlled access to resources needed by the function.

Lambda integrates with S3 for event-driven processing, DynamoDB for data manipulation and triggers, and API Gateway for building serverless APIs; common use cases include processing S3 uploads, responding to DynamoDB changes, and handling API requests.

Strategies for monitoring and debugging Lambda functions include using CloudWatch Logs for logging and error tracking, CloudWatch Metrics for performance monitoring, and CloudWatch Alarms for alerting, along with AWS X-Ray for tracing and debugging.

Amazon S3 offers storage classes including **Standard** for frequently accessed data, **Intelligent-Tiering** for automatic cost optimization, **One Zone-IA** for infrequent access in a single zone, **Glacier** for long-term archival, and **Glacier Deep Archive** for rare access at the lowest cost.