Dev Logging and Monitoring Setup Guide
======================================

Create a logging and monitoring setup guide for [application].

Application details:
- Application: [name]
- Language: [language]
- Cloud: [AWS/GCP/Azure]
- Current logging: [none/console only/structured]
- Monitoring tool: [DataDog/New Relic/Prometheus/CloudWatch]

LOGGING AND MONITORING GUIDE

1. LOGGING BEST PRACTICES

   LOG LEVELS
   - ERROR: [application errors requiring immediate attention]
   - WARN: [unexpected situations that are not errors]
   - INFO: [significant business events]
   - DEBUG: [diagnostic information — disabled in production]

   WHAT TO LOG
   ✓ Application start/stop
   ✓ All errors with stack traces
   ✓ External API calls (request/response/duration)
   ✓ Database query duration (slow queries)
   ✓ Authentication events (login/logout/failed)
   ✓ Business events (order placed/payment processed)
   ✓ Background job start/completion/failure

   WHAT NOT TO LOG
   ✗ Passwords or secrets
   ✗ Full credit card numbers
   ✗ PII without masking
   ✗ Raw SQL with parameters (mask values)

2. STRUCTURED LOGGING FORMAT
   ```json
   {
     "timestamp": "2024-01-15T10:30:00Z",
     "level": "INFO",
     "service": "order-service",
     "traceId": "abc123",
     "userId": "user_456",
     "event": "order.created",
     "orderId": "ord_789",
     "amount": 99.99,
     "duration_ms": 145
   }
   ```

3. METRICS TO TRACK

   GOLDEN SIGNALS
   - Latency: [p50/p95/p99 response times]
   - Traffic: [requests per second]
   - Errors: [error rate %]
   - Saturation: [CPU/memory/queue depth]

   BUSINESS METRICS
   - [Orders per minute]
   - [Active users]
   - [Conversion rate]
   - [Revenue per hour]

4. ALERTING RULES

   | Alert | Condition | Severity | Action |
   | High error rate | >1% for 5min | P1 | Page on-call |
   | High latency | p99 >2s for 5min | P2 | Notify team |
   | Memory high | >85% for 10min | P2 | Notify |
   | Disk space | >80% | P3 | Ticket |

5. DISTRIBUTED TRACING
   - Correlation ID: [generate at entry point]
   - Propagate: [through all service calls]
   - Log with every request: [trace ID in all logs]
   - Tool: [Jaeger/Zipkin/AWS X-Ray]

6. DASHBOARD SETUP
   - Overview dashboard: [key service health]
   - Error dashboard: [error breakdown]
   - Performance dashboard: [latency/throughput]
   - Business dashboard: [key business metrics]
   - On-call dashboard: [what responder needs first]

Source: https://promptzyo.com/prompt/dev-logging-and-monitoring-setup-guide