Traditional Analytics to ML Platforms
A guide to migrating from rules-based analytics to ML-powered platforms with model training and deployment.
Executive Summary
A fraud detection team used 500 SQL rules (if-then) that caught only 60% of fraud. Over 10 months, they migrated to an ML platform with feature store, XGBoost models, and real-time inference, increasing fraud detection to 92% with 50% fewer false positives. This guide covers feature engineering, model development, and replacing rules with ML incrementally.
Why Migrate from Rules-Based Analytics
The rules-based system was brittle—500 rules required 10 engineers to maintain, and fraudsters easily bypassed static rules.
- → 60% fraud detection rate (missed 40% of fraud)
- → 15% false positive rate (legitimate transactions declined)
- → 10 engineers full-time on rule maintenance ($1M/year)
- → Rules stale within weeks (fraudsters adapt)
ML Platform Readiness
The team spent 3 months on preparation: building feature store (Feast), setting up ML infrastructure, and creating label training data.
- • Feature store (Feast, Tecton)
- • Labeled fraud data (6 months historical)
- • ML training infrastructure (SageMaker, Vertex AI)
- • Real-time inference platform (Kafka + Flink)
- • A/B testing framework
Rules-Based Assessment
The system had 500 SQL rules, 50 tables, and 100 dashboards. Rules were updated weekly based on fraud patterns.
Technical Debt
- • Rules interdependent (changing one breaks others)
- • No automated testing (deployments risky)
- • Rules stale within weeks (fraudsters adapt)
- • High false positive rate (customer complaints)
Risks
- • ML model interpretability (explain to compliance)
- • Training-serving skew (feature differences)
- • Model degradation over time (concept drift)
- • Integration with legacy rules during migration
Target ML Platform Architecture
The target was real-time fraud detection with feature store, ML models, and fallback to rules.
10-Month ML Platform Migration
Step 1: Phase 1: Foundation (Month 1-3)
Built feature store, labeled 1M transactions, trained baseline XGBoost model (AUC 0.85).
Step 2: Phase 2: Shadow Mode (Month 4-6)
Deployed model in shadow mode (no action), compared predictions to rules.
Step 3: Phase 3: Soft Rollout (Month 7-9)
Model actioned only for high-confidence predictions (30% of traffic).
Step 4: Phase 4: Full Cutover (Month 10)
Model for 100% of traffic, rules as fallback only.
Rules to Features Transformation
Each SQL rule was converted to a feature (input to ML model). Historical feature values computed for training.
- • Rule → feature (e.g., transaction amount > $1000 → amount feature)
- • Point-in-time correctness (no future data leakage)
- • Feature backfill for historical training data
- • Online/offline consistency (same feature logic)
Common Analytics to ML Mistakes
No feature store
Impact: Training-serving skew (model accuracy 20% lower in production)
Prevention: Feast or similar for point-in-time correct features
Skipping shadow mode
Impact: Model performs worse than rules (50% false positive increase)
Prevention: 3-month shadow mode, compare metrics
Not monitoring data drift
Impact: Model degrades silently (fraud detection 90% → 60% in 2 months)
Prevention: Evidently + daily model performance monitoring
Model too complex for real-time
Impact: Inference latency 500ms (transaction times out)
Prevention: Latency budget 50ms; use XGBoost not deep learning
Migration Success Metrics
Who Should Lead Analytics to ML Migration
Recommended Roles
Required Experience
- • Feature store implementation (Feast)
- • Real-time ML inference (50ms latency)
- • Fraud detection domain knowledge
- • A/B testing for ML models
Related Roles
Frequently Asked Questions
- What if ML model is less interpretable than rules?
- Use SHAP for explainability. Regulators accept model explanations with SHAP values.
- How to handle concept drift?
- Daily retraining with new labeled data. Monitor AUC and alert on 5% drop.
- Can we keep some rules alongside ML?
- Yes—ensemble approach: rules for clear-cut cases, ML for complex. Start with 30% ML, increase over time.