This article does a great job breaking down redundancy and persistence as essential components for improving application availability. I appreciate the clear explanation of synchronous vs. asynchronous replication and their trade-offs—balancing speed, consistency, and data integrity is always tricky. The AWS examples, especially around RDS and DynamoDB, highlight practical solutions and make these concepts actionable. Looking forward to the next part of the series to see how these foundations tie into more advanced strategies like multi-region active-active setups!