To proactively spot latency spikes on Google Cloud before customers do, SREs should use a multi-layered approach, creating custom dashboards in Cloud Monitoring that combine platform-wide network intelligence with deep, service-specific metrics. Early warnings can come from either a degradation of the underlying network or from saturation in a specific application service.
  - Layer 1: Network Intelligence Center
The Google Cloud Performance Dashboard provides a high-level view of network health. It's the first place to look for signs of a broader network issue, which can often precede application-level problems. 
  - Layer 2: Application-layer observability
Custom dashboards in Cloud Monitoring should be configured to capture fine-grained metrics for your specific workloads. This provides early warnings of application-level saturation that can cause user-facing latency.
  - Layer 3: Tracing and logging
For deeper analysis during an incident, integrate and analyze data from Cloud Trace and Cloud Logging.