To improve application reliability, we design our applications to be deployed across multiple AWS Availability Zones (AZs) within the same Region. By distributing our application’s components—such as web servers, databases, and application services—across multiple AZs, we ensure high availability and fault tolerance. Each AZ is treated as an independent failure domain, meaning that if one AZ experiences issues, the other AZs can continue running the application without disruption. We leverage AWS services like Elastic Load Balancing (ELB) to distribute traffic across instances in different AZs, ensuring consistent performance. For data storage, we use Amazon RDS with Multi-AZ deployments for automated failover and Amazon S3, which replicates data across AZs for durability. Additionally, we implement auto-scaling policies to dynamically adjust resources based on demand, ensuring applications remain available and responsive. This approach enhances resilience, minimizes downtime, and improves the overall reliability of our applications.