ADVANCED // CUSTOM API
MODULE 11 // OBSERVABILITY
Monitoring & Analytics.
Implement comprehensive monitoring for API health and usage patterns.
OBSERVABILITY STRATEGY
API observability requires three pillars: metrics (quantitative measurements), logs (event records), and traces (request journeys). Together they enable understanding and debugging.
Key metrics: request rate, error rate, latency percentiles (P50, P95, P99), and saturation (resource utilization). Alert on anomalies, not just thresholds.
Usage analytics inform product decisions: which endpoints are popular, where do users struggle, what features are underutilized. Analytics complement operational monitoring.
P99 < 500ms
Latency SLO
99th percentile response time. Ensures consistent performance for all users.
< 0.1%
Error Rate
Server-side error percentage. Indicates API health and reliability.
< 80%
Saturation
Resource utilization. Headroom for traffic spikes.
KNOWLEDGE CHECK // Q11
Why monitor P99 latency rather than average?