Sentry and VMware Tanzu Observability (Wavefront) are used to proactively monitor and fix issues in a microservices-based app, such as Cloud Marketplace. The engineering team uses these tools to ensure the app meets its SLAs, with Wavefront monitoring the app infrastructure stack, including VMs, K8S clusters, and Prometheus services. Sentry is used for error monitoring, providing real-time alerting, exception grouping, and deduplication of exceptions, helping the team respond quickly to bugs and issues, reducing time to resolution from weeks to hours, and improving customer experience. The combination of these tools enables the team to build an observable system and react quickly to observability alerts, making it easier to identify and fix issues in the app's long tail of changes.