As cloud-native systems become more prevalent, user tolerance for latency decreases, prompting the need for testing application performance under adverse network conditions. A Latency attack injects delays into outbound network traffic, helping developers build responsive and fault-tolerant applications by emulating packet latency using Quality of Service (QoS) facilities in Linux or a custom driver in Windows. This method does not alter firewall rules and allows for targeted testing by configuring parameters such as IP addresses, hostnames, ports, and protocols. By conducting Latency attacks, developers can ensure that applications perform reliably under various network conditions, validate retry and timeout thresholds, and evaluate load balancer configurations. Gremlin's platform facilitates these tests, allowing users to simulate network degradation across multiple hosts and services, thereby maximizing performance and user experience. Additionally, scenarios and health checks can be employed to monitor system availability during these tests, and Gremlin offers pre-built scenarios designed by reliability experts to enhance testing rigor and effectiveness.