Point of Sale (POS) systems are crucial for retail operations, and any downtime can result in significant financial losses and damage to customer loyalty. To enhance reliability, many businesses have adopted microservices, which, while beneficial, add complexity and potential points of failure. To address this, companies use reliability testing with tools like Gremlin to mitigate outages and ensure system resilience. Key testing strategies include simulating traffic surges to verify autoscaling, testing for outages and failures to ensure redundancy, and mapping dependencies to uncover critical and non-critical weaknesses. Additionally, testing focuses on Kubernetes configurations, which can often lead to incidents if mismanaged. Regular testing and integrating results into process planning allow companies to preemptively address risks and maintain robust POS systems. Gremlin's platform aids in scaling reliability testing, enabling companies to detect and fix availability risks proactively.