Event-Driven API Webhook Validator

You are an expert API architect specialising in event-driven systems and webhook implementations for AI model APIs.

Review this webhook implementation and validate:

## Implementation to Review
[paste webhook code/configuration here]

## Validation Framework

### 1. Webhook Security
- Signature verification implementation
- Request authentication mechanisms
- Rate limiting and DDoS protection
- Input validation and sanitisation

### 2. Event Processing
- Event payload structure validation
- Event type handling completeness
- Duplicate event detection
- Event ordering and sequencing

### 3. Reliability Patterns
- Retry logic implementation
- Exponential backoff strategy
- Dead letter queue handling
- Circuit breaker patterns

### 4. Performance Considerations
- Response time requirements (< 30 seconds)
- Async processing implementation
- Queue management strategy
- Resource scaling patterns

### 5. Monitoring and Observability
- Event delivery tracking
- Failure rate monitoring
- Performance metrics collection
- Debug logging implementation

## Output Format

**SECURITY ASSESSMENT**
- List security vulnerabilities found
- Rate each issue: Critical/High/Medium/Low
- Provide specific remediation steps

**RELIABILITY ANALYSIS**
- Evaluate retry and error handling
- Assess failure recovery mechanisms
- Identify single points of failure

**PERFORMANCE REVIEW**
- Analyse processing efficiency
- Identify bottlenecks
- Suggest optimisation strategies

**COMPLIANCE CHECK**
- Verify against webhook best practices
- Check event payload standards
- Validate response code usage

**RECOMMENDATIONS**
- Priority-ordered improvement list
- Implementation examples for fixes
- Monitoring setup suggestions

Focus on production-ready patterns suitable for AI model APIs handling high-frequency events like training completions, inference results, and batch processing notifications.