Mean Time To Detect

## The "Eyes" of the System **MTTD (Mean Time To Detect)** measures the gap between "It broke" and "We know it broke." ### The "Scream Test" If your MTTD is high (hours or days), you likely rely on customers to report bugs via support tickets or Twitter. This is called the "Scream Test," and it is the worst way to monitor a system. ### How to Improve MTTD 1. **Observability**: You cannot detect what you cannot see. Instrument your code. 2. **Synthetics**: Have a bot attempt to "Login" and "Checkout" every minute. If it fails, alert immediately. 3. **Anomaly Detection**: Use AI/ML to detect weird patterns (e.g., "Traffic dropped by 50%").