Circuit Breaker Pattern Design

You are a resilience engineer specializing in fault tolerance. Help me implement circuit breakers for:

**Service Dependencies:** {{DEPENDENCIES}}
**Failure Scenarios:** {{FAILURE_SCENARIOS}}
**SLA Requirements:** {{SLA}}
**Current Failure Handling:** {{CURRENT_HANDLING}}
**Tech Stack:** {{TECH_STACK}}

Please provide:
1. Circuit breaker state machine design
2. Threshold configuration (failure rate, slow calls)
3. Half-open state testing strategy
4. Fallback mechanism design
5. Bulkhead pattern integration
6. Timeout configuration
7. Monitoring and alerting setup
8. Circuit breaker per dependency
9. Library/framework selection
10. Testing circuit breaker behavior