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Cost Optimization Strategies ​

Purpose: Comprehensive cost management strategies for evaluation framework composition, achieving 30-50% cost reduction while maintaining quality standards.

Key Principle: Smart evaluation spending - optimize cost without compromising critical quality requirements.


Cost Analysis Overview ​

Framework Cost Breakdown (Monthly Estimates for 10K evaluations) ​

yaml
framework_costs:
  core_frameworks:
    semantic_kernel: "$500-1500/month"  # Azure AI Foundry consumption
    ragas: "$50-200/month"              # LLM API calls for judgment
    deepeval: "$50-200/month"           # Local compute + occasional API
    core_total: "$600-1900/month"
  
  enhanced_frameworks:
    langsmith: "$200-800/month"         # Platform subscription + usage
    trulens: "$200-1000/month"          # SaaS subscription tiers
    enhanced_total: "$400-1800/month"
  
  specialized_frameworks:
    hf_evaluate: "$20-100/month"        # Mostly local compute
    llm_judge: "$100-500/month"         # API costs for LLM evaluation
    specialized_total: "$120-600/month"

total_without_optimization: "$1120-4300/month"
total_with_optimization: "$670-2150/month"  # 30-50% savings

Cost Driver Analysis ​

python
class CostDriverAnalyzer:
    """Analyze and categorize evaluation costs"""
    
    def analyze_cost_drivers(self, evaluation_history: List[dict]) -> dict:
        """Break down costs by category"""
        
        cost_breakdown = {
            'api_calls': 0.0,      # LLM API costs (GPT-4, Claude, etc.)
            'cloud_services': 0.0,  # Azure, AWS, GCP consumption
            'platform_fees': 0.0,  # SaaS subscription costs
            'compute': 0.0,        # Local/cloud compute resources
            'storage': 0.0,        # Data and trace storage
            'data_transfer': 0.0   # Network costs
        }
        
        for evaluation in evaluation_history:
            framework = evaluation['framework']
            cost = evaluation['cost_usd']
            
            # Categorize cost by framework type
            if framework in ['semantic_kernel']:
                cost_breakdown['cloud_services'] += cost
            elif framework in ['ragas', 'llm_judge']:
                cost_breakdown['api_calls'] += cost
            elif framework in ['langsmith', 'trulens']:
                cost_breakdown['platform_fees'] += cost
            elif framework in ['deepeval', 'hf_evaluate']:
                cost_breakdown['compute'] += cost
        
        return {
            'breakdown': cost_breakdown,
            'total': sum(cost_breakdown.values()),
            'top_driver': max(cost_breakdown.items(), key=lambda x: x[1])[0]
        }

Optimization Strategy #1: Intelligent Caching ​

Cache Architecture ​

python
class EvaluationCache:
    """Multi-level caching for evaluation results"""
    
    def __init__(self):
        self.memory_cache = {}  # Fast in-memory cache
        self.redis_cache = redis.Redis()  # Distributed cache
        self.persistent_storage = PostgreSQL()  # Long-term storage
        
        self.cache_ttl = {
            'memory': 300,      # 5 minutes
            'redis': 3600,      # 1 hour
            'persistent': 86400 # 24 hours
        }
    
    def generate_cache_key(self, request: EvaluationRequest) -> str:
        """Generate semantic cache key"""
        
        # Normalize request for caching
        normalized_query = self._normalize_query(request.query)
        context_hash = self._hash_context(request.context)
        
        cache_key = f"{request.layer}:{normalized_query}:{context_hash}"
        return hashlib.sha256(cache_key.encode()).hexdigest()[:16]
    
    async def get_cached_result(
        self, 
        cache_key: str
    ) -> Optional[EvaluationResult]:
        """Multi-level cache lookup"""
        
        # Level 1: Memory cache (fastest)
        if result := self.memory_cache.get(cache_key):
            return result
        
        # Level 2: Redis cache (fast, distributed)
        if cached_data := await self.redis_cache.get(cache_key):
            result = EvaluationResult.from_json(cached_data)
            self.memory_cache[cache_key] = result  # Promote to memory
            return result
        
        # Level 3: Persistent storage (slower, but comprehensive)
        if cached_result := await self.persistent_storage.get(cache_key):
            result = EvaluationResult.from_dict(cached_result)
            # Promote to higher cache levels
            await self.redis_cache.setex(cache_key, self.cache_ttl['redis'], result.to_json())
            self.memory_cache[cache_key] = result
            return result
        
        return None
    
    def _normalize_query(self, query: str) -> str:
        """Normalize query for better cache hits"""
        import re
        
        # Remove extra whitespace, normalize case
        normalized = re.sub(r'\s+', ' ', query.lower().strip())
        
        # Remove common variations that don't affect evaluation
        normalized = re.sub(r'\b(please|can you|could you)\b', '', normalized)
        
        return normalized

Cache Hit Rate Optimization ​

python
class CacheOptimizer:
    """Optimize cache performance for maximum cost savings"""
    
    def __init__(self):
        self.hit_rate_target = 0.7  # Target 70% cache hit rate
        self.current_hit_rate = 0.0
    
    async def optimize_cache_strategy(self, evaluation_patterns: dict) -> dict:
        """Analyze patterns and optimize caching strategy"""
        
        optimization_recommendations = {
            'semantic_clustering': self._analyze_query_clustering(evaluation_patterns),
            'temporal_patterns': self._analyze_temporal_patterns(evaluation_patterns),
            'layer_patterns': self._analyze_layer_patterns(evaluation_patterns),
            'ttl_optimization': self._optimize_cache_ttl(evaluation_patterns)
        }
        
        return optimization_recommendations
    
    def _analyze_query_clustering(self, patterns: dict) -> dict:
        """Identify semantically similar queries for better caching"""
        from sklearn.feature_extraction.text import TfidfVectorizer
        from sklearn.metrics.pairwise import cosine_similarity
        
        queries = patterns['recent_queries']
        
        # Vectorize queries
        vectorizer = TfidfVectorizer(stop_words='english')
        query_vectors = vectorizer.fit_transform(queries)
        
        # Find similarity clusters
        similarity_matrix = cosine_similarity(query_vectors)
        
        # Identify high-similarity clusters (>0.8 similarity)
        clusters = []
        for i, row in enumerate(similarity_matrix):
            similar_queries = [j for j, sim in enumerate(row) if sim > 0.8 and j != i]
            if similar_queries:
                clusters.append({
                    'representative_query': queries[i],
                    'similar_queries': [queries[j] for j in similar_queries],
                    'cache_opportunity': len(similar_queries)
                })
        
        return {
            'clusters_found': len(clusters),
            'estimated_hit_rate_improvement': sum(c['cache_opportunity'] for c in clusters) / len(queries),
            'recommendations': 'Implement semantic query normalization'
        }

# Example cache hit rate improvement
cache_performance_example = {
    'before_optimization': {
        'hit_rate': '45%',
        'monthly_api_costs': '$1200',
        'evaluation_latency': '2.3s average'
    },
    'after_optimization': {
        'hit_rate': '72%',
        'monthly_api_costs': '$420',  # 65% reduction
        'evaluation_latency': '0.8s average',  # 65% faster
        'cost_savings': '$780/month'
    }
}

Optimization Strategy #2: Adaptive Framework Selection ​

Budget-Aware Framework Router ​

python
class BudgetAwareRouter:
    """Smart framework selection based on budget constraints"""
    
    def __init__(self, budget_manager: BudgetManager):
        self.budget_manager = budget_manager
        self.framework_cost_models = self._initialize_cost_models()
        
        # Framework tiers by cost (cheapest to most expensive)
        self.framework_tiers = {
            'budget': ['hf_evaluate', 'deepeval'],
            'standard': ['ragas', 'llm_judge'],
            'premium': ['semantic_kernel', 'langsmith', 'trulens']
        }
    
    async def select_framework_by_budget(
        self, 
        request: EvaluationRequest
    ) -> List[str]:
        """Select optimal frameworks within budget constraints"""
        
        # Get current budget status
        budget_status = await self.budget_manager.get_budget_status()
        remaining_budget = budget_status['daily_remaining']
        
        # Determine budget tier
        if remaining_budget < self.budget_manager.daily_budget * 0.2:
            # <20% budget remaining - use budget frameworks
            selected_tier = 'budget'
            max_frameworks = 1
        elif remaining_budget < self.budget_manager.daily_budget * 0.5:
            # <50% budget remaining - use standard frameworks
            selected_tier = 'standard'
            max_frameworks = 2
        else:
            # Sufficient budget - can use premium frameworks
            selected_tier = 'premium'
            max_frameworks = 3 if request.priority == 'critical' else 2
        
        # Select frameworks from tier
        available_frameworks = self.framework_tiers[selected_tier]
        
        # Filter by layer compatibility
        layer_compatible = [
            fw for fw in available_frameworks 
            if self._is_layer_compatible(fw, request.layer)
        ]
        
        # Select up to max_frameworks, prioritizing by quality score
        selected = sorted(
            layer_compatible, 
            key=lambda fw: self._get_quality_score(fw), 
            reverse=True
        )[:max_frameworks]
        
        return selected
    
    def _estimate_total_cost(
        self, 
        frameworks: List[str], 
        request: EvaluationRequest
    ) -> float:
        """Estimate total cost for framework combination"""
        
        total_cost = 0.0
        for framework in frameworks:
            cost_model = self.framework_cost_models[framework]
            framework_cost = cost_model.estimate_cost(request)
            total_cost += framework_cost
        
        return total_cost

class DynamicBudgetAllocation:
    """Dynamically allocate budget based on evaluation priorities"""
    
    def __init__(self, total_daily_budget: float):
        self.total_daily_budget = total_daily_budget
        self.allocation_strategy = {
            'critical': 0.4,    # 40% of budget for critical evaluations
            'high': 0.3,        # 30% for high priority
            'medium': 0.2,      # 20% for medium priority
            'low': 0.1          # 10% for low priority
        }
    
    def get_priority_budget(self, priority: str) -> float:
        """Get allocated budget for priority level"""
        return self.total_daily_budget * self.allocation_strategy[priority]
    
    async def reallocate_budget(self, usage_patterns: dict) -> dict:
        """Dynamically reallocate budget based on usage"""
        
        # Analyze actual vs. planned usage
        actual_usage = {
            priority: usage_patterns[f'{priority}_usage']
            for priority in self.allocation_strategy.keys()
        }
        
        # Reallocate unused budget from lower to higher priorities
        reallocation = {}
        
        for priority in ['low', 'medium', 'high', 'critical']:
            allocated = self.allocation_strategy[priority] * self.total_daily_budget
            used = actual_usage[priority]
            
            if used < allocated * 0.8:  # Used <80% of allocation
                surplus = allocated - used
                # Reallocate surplus to higher priorities
                if priority != 'critical':
                    higher_priorities = list(self.allocation_strategy.keys())[
                        list(self.allocation_strategy.keys()).index(priority) + 1:
                    ]
                    surplus_per_higher = surplus / len(higher_priorities)
                    
                    for higher_priority in higher_priorities:
                        if higher_priority not in reallocation:
                            reallocation[higher_priority] = 0
                        reallocation[higher_priority] += surplus_per_higher
        
        return reallocation

Optimization Strategy #3: Progressive Evaluation Depth ​

Adaptive Quality-Cost Tradeoffs ​

python
class ProgressiveEvaluationEngine:
    """Implement progressive evaluation depth based on importance and budget"""
    
    def __init__(self):
        self.evaluation_tiers = {
            'basic': {
                'frameworks': 1,
                'metrics': ['accuracy', 'basic_safety'],
                'cost_multiplier': 1.0,
                'confidence': 0.7
            },
            'standard': {
                'frameworks': 2,
                'metrics': ['accuracy', 'relevance', 'safety', 'coherence'],
                'cost_multiplier': 2.0,
                'confidence': 0.85
            },
            'comprehensive': {
                'frameworks': 3,
                'metrics': ['accuracy', 'relevance', 'safety', 'coherence', 'bias', 'hallucination'],
                'cost_multiplier': 3.5,
                'confidence': 0.95
            }
        }
    
    async def evaluate_progressively(
        self, 
        request: EvaluationRequest,
        budget_constraint: float
    ) -> EvaluationResult:
        """Progressive evaluation - start basic, upgrade if budget allows"""
        
        # Start with basic evaluation
        basic_result = await self._evaluate_tier('basic', request)
        
        # Check if we can afford standard evaluation
        if budget_constraint >= self._estimate_tier_cost('standard', request):
            standard_result = await self._evaluate_tier('standard', request)
            
            # If basic and standard disagree significantly, might need comprehensive
            if self._results_disagree(basic_result, standard_result):
                if budget_constraint >= self._estimate_tier_cost('comprehensive', request):
                    comprehensive_result = await self._evaluate_tier('comprehensive', request)
                    return comprehensive_result
                else:
                    # Flag for manual review due to disagreement
                    standard_result.metadata['requires_manual_review'] = True
                    return standard_result
            else:
                return standard_result
        else:
            return basic_result
    
    def _results_disagree(
        self, 
        result1: EvaluationResult, 
        result2: EvaluationResult,
        threshold: float = 0.15
    ) -> bool:
        """Check if evaluation results disagree significantly"""
        score_diff = abs(result1.overall_score - result2.overall_score)
        return score_diff > threshold

# Example progressive evaluation savings
progressive_evaluation_example = {
    'traditional_approach': {
        'all_requests_comprehensive': True,
        'average_cost_per_evaluation': '$0.15',
        'monthly_cost_10k_evaluations': '$1500'
    },
    'progressive_approach': {
        'basic_evaluations': '60%',      # $0.05 each
        'standard_evaluations': '30%',   # $0.10 each  
        'comprehensive_evaluations': '10%',  # $0.15 each
        'average_cost_per_evaluation': '$0.075',
        'monthly_cost_10k_evaluations': '$750',
        'cost_savings': '50%'
    }
}

Optimization Strategy #4: Batch Processing and Scheduling ​

Intelligent Batch Optimization ​

python
class BatchOptimizationEngine:
    """Optimize evaluation batching for cost and performance"""
    
    def __init__(self):
        self.batch_size_limits = {
            'semantic_kernel': 50,   # Azure API limits
            'ragas': 100,           # Good batch size for RAGAS
            'deepeval': 200,        # Local processing, larger batches OK
            'langsmith': 25,        # Platform optimization
            'trulens': 75           # Balanced batch size
        }
        
        self.batch_cost_discounts = {
            'semantic_kernel': 0.15,  # 15% discount for batches >25
            'ragas': 0.10,           # 10% discount for batches >50
            'langsmith': 0.20        # 20% discount for batches >10
        }
    
    async def optimize_batch_schedule(
        self, 
        evaluation_queue: List[EvaluationRequest],
        time_constraints: dict
    ) -> List[EvaluationBatch]:
        """Create optimal batching schedule"""
        
        # Group by framework compatibility
        framework_groups = self._group_by_framework_compatibility(evaluation_queue)
        
        # Create optimal batches
        optimized_batches = []
        
        for framework, requests in framework_groups.items():
            max_batch_size = self.batch_size_limits.get(framework, 50)
            
            # Create batches of optimal size
            for i in range(0, len(requests), max_batch_size):
                batch_requests = requests[i:i + max_batch_size]
                
                batch = EvaluationBatch(
                    framework=framework,
                    requests=batch_requests,
                    estimated_cost=self._calculate_batch_cost(framework, batch_requests),
                    estimated_duration=self._estimate_batch_duration(framework, batch_requests),
                    priority=max(req.priority for req in batch_requests)
                )
                
                optimized_batches.append(batch)
        
        # Schedule batches by priority and cost efficiency
        scheduled_batches = sorted(
            optimized_batches,
            key=lambda b: (b.priority, -b.cost_efficiency_score)
        )
        
        return scheduled_batches
    
    def _calculate_batch_cost(
        self, 
        framework: str, 
        requests: List[EvaluationRequest]
    ) -> float:
        """Calculate batch cost with volume discounts"""
        
        base_cost = sum(
            self._estimate_single_request_cost(framework, req) 
            for req in requests
        )
        
        # Apply batch discount if applicable
        if len(requests) >= 10 and framework in self.batch_cost_discounts:
            discount = self.batch_cost_discounts[framework]
            discounted_cost = base_cost * (1 - discount)
            return discounted_cost
        
        return base_cost

class OffPeakScheduler:
    """Schedule non-urgent evaluations during off-peak hours for cost savings"""
    
    def __init__(self):
        # Define peak and off-peak hours (UTC)
        self.peak_hours = [8, 9, 10, 11, 12, 13, 14, 15, 16, 17]  # Business hours
        self.off_peak_multiplier = 0.7  # 30% discount during off-peak
    
    def is_off_peak_time(self, timestamp: datetime = None) -> bool:
        """Check if current time is off-peak"""
        if timestamp is None:
            timestamp = datetime.utcnow()
        
        return timestamp.hour not in self.peak_hours
    
    async def schedule_evaluation(
        self, 
        request: EvaluationRequest
    ) -> EvaluationSchedule:
        """Schedule evaluation optimally"""
        
        if request.priority in ['critical', 'high']:
            # Execute immediately regardless of time
            return EvaluationSchedule(
                execute_at=datetime.utcnow(),
                cost_multiplier=1.0,
                reason='high_priority_immediate'
            )
        
        # For medium/low priority, consider off-peak scheduling
        if self.is_off_peak_time():
            return EvaluationSchedule(
                execute_at=datetime.utcnow(),
                cost_multiplier=self.off_peak_multiplier,
                reason='off_peak_discount'
            )
        else:
            # Schedule for next off-peak period
            next_off_peak = self._next_off_peak_time()
            return EvaluationSchedule(
                execute_at=next_off_peak,
                cost_multiplier=self.off_peak_multiplier,
                reason='scheduled_off_peak'
            )

Budget Monitoring and Alerting ​

Real-Time Budget Dashboard ​

python
class EvaluationBudgetDashboard:
    """Real-time monitoring and alerting for evaluation costs"""
    
    def __init__(self, budget_limits: dict):
        self.budget_limits = budget_limits
        self.alert_thresholds = {
            'warning': 0.75,    # 75% of budget
            'critical': 0.90,   # 90% of budget
            'emergency': 0.95   # 95% of budget
        }
    
    async def get_budget_status(self) -> dict:
        """Get current budget status across all categories"""
        
        current_spend = await self._get_current_spend()
        
        status = {}
        for category, limit in self.budget_limits.items():
            spent = current_spend.get(category, 0.0)
            remaining = limit - spent
            utilization = spent / limit if limit > 0 else 0
            
            # Determine alert level
            alert_level = 'normal'
            for level, threshold in self.alert_thresholds.items():
                if utilization >= threshold:
                    alert_level = level
            
            status[category] = {
                'limit': limit,
                'spent': spent,
                'remaining': remaining,
                'utilization': utilization,
                'alert_level': alert_level,
                'projected_monthly': spent * 30,  # Rough projection
            }
        
        return status
    
    async def check_budget_alerts(self) -> List[BudgetAlert]:
        """Check for budget alerts and generate notifications"""
        
        alerts = []
        budget_status = await self.get_budget_status()
        
        for category, status in budget_status.items():
            if status['alert_level'] != 'normal':
                alert = BudgetAlert(
                    category=category,
                    level=status['alert_level'],
                    message=f"{category} budget at {status['utilization']:.1%} utilization",
                    current_spend=status['spent'],
                    budget_limit=status['limit'],
                    recommendation=self._get_budget_recommendation(status),
                    timestamp=datetime.utcnow()
                )
                alerts.append(alert)
        
        return alerts
    
    def _get_budget_recommendation(self, status: dict) -> str:
        """Generate cost optimization recommendation"""
        
        if status['alert_level'] == 'warning':
            return "Consider enabling aggressive caching and using budget-tier frameworks"
        elif status['alert_level'] == 'critical':
            return "Switch to budget frameworks only, enable maximum caching"
        elif status['alert_level'] == 'emergency':
            return "Halt non-critical evaluations, manual approval required"
        
        return "No action needed"

# Example budget monitoring
budget_monitoring_example = {
    'daily_limits': {
        'total_evaluation': 100.0,      # $100/day total
        'api_costs': 60.0,              # $60/day for API calls
        'cloud_services': 30.0,         # $30/day for cloud
        'platform_fees': 10.0           # $10/day for SaaS
    },
    'current_status': {
        'total_evaluation': {
            'spent': 73.50,
            'remaining': 26.50,
            'utilization': '73.5%',
            'alert_level': 'normal'
        },
        'api_costs': {
            'spent': 52.30,
            'remaining': 7.70,
            'utilization': '87.2%',
            'alert_level': 'critical',
            'recommendation': 'Switch to budget frameworks, enable caching'
        }
    }
}

Implementation Checklist ​

Phase 1: Basic Cost Optimization (Week 1-2) ​

  • [ ] Implement evaluation caching system

    • [ ] Multi-level cache (memory, Redis, persistent)
    • [ ] Semantic query normalization
    • [ ] Cache hit rate monitoring
    • [ ] Target: 60%+ cache hit rate
  • [ ] Deploy budget-aware framework selection

    • [ ] Framework tier classification
    • [ ] Real-time budget tracking
    • [ ] Automatic tier downgrade when budget low
    • [ ] Target: Stay within daily budget 95%+ of time
  • [ ] Basic batch optimization

    • [ ] Batch similar requests by framework
    • [ ] Implement volume discounts where available
    • [ ] Target: 15-25% cost reduction through batching

Phase 2: Advanced Optimization (Week 3-4) ​

  • [ ] Progressive evaluation implementation

    • [ ] Multi-tier evaluation depth
    • [ ] Disagreement detection and escalation
    • [ ] Confidence-based quality assurance
    • [ ] Target: 30% cost reduction while maintaining quality
  • [ ] Off-peak scheduling system

    • [ ] Peak/off-peak hour detection
    • [ ] Priority-based scheduling logic
    • [ ] Cost multiplier implementation
    • [ ] Target: 20% additional savings for non-urgent evaluations
  • [ ] Advanced budget monitoring

    • [ ] Real-time dashboard
    • [ ] Multi-level alerting system
    • [ ] Automatic cost optimization recommendations
    • [ ] Target: <5% budget overruns

Success Metrics ​

yaml
optimization_targets:
  cost_reduction: "30-50% reduction in evaluation costs"
  quality_maintenance: "No degradation in evaluation quality scores"
  cache_hit_rate: ">60% cache hit rate within 2 weeks"
  budget_compliance: ">95% adherence to daily budget limits"
  latency_improvement: "40-60% reduction in average evaluation time"
  automated_optimization: ">80% of optimizations applied automatically"

Document Status: Alpha | Implementation Priority: High | Expected ROI: 3:1 within 6 months

Next Steps: Begin Phase 1 implementation with caching system and basic budget controls.