Cloud outages, though infrequent, can have severe impacts, as highlighted by a recent AWS DNS failure in us-east-1 that disrupted multiple services like DynamoDB and Network Load Balancers. This event underscores the importance of application resilience, which can be tested using LocalStack’s Chaos API to simulate failures such as throttling, latency, and service errors in key AWS services within a local environment. Chaos engineering, the practice of intentionally injecting failures to observe system behavior under stress, helps ensure applications gracefully handle real-world failures. This post guides users through emulating AWS services locally, injecting failure scenarios with the Chaos API, and monitoring application responses, ultimately building a more robust system without affecting production environments. By leveraging LocalStack, developers can achieve a repeatable and safe workflow to test and strengthen their applications against potential cloud service disruptions.