"CPU steal" is a property of virtual environments where hypervisors reclaim CPU cycles from instances that have reached their capacity or are facing hardware limitations. This can lead to inconsistent performance in AWS instances. To detect CPU steal, track the system metric "system.cpu.stolen" using Datadog. By comparing this metric with the CPU idle metric (system.cpu.idle), users can determine if stolen CPU is due to hypervisor quotas or other tenants on the same hardware demanding more cycles. High variations in CPU steal for different occurrences of CPU idle going to zero may indicate that an application's performance is being negatively impacted by other instances sharing the same hardware.