A cascaded machine learning system with 30 expert rules, Bayesian Neural Network, and XGBoost/LightGBM/CatBoost ensemble achieving 83% recall at 52% precision.
Digital payment fraud is a $50+ billion crisis in 2025, with losses projected to exceed $343 billion by 2027. Traditional fraud detection systems face a critical flaw:
| Challenge | Traditional Systems | Our Solution |
|---|---|---|
| False Positive Rate | 90-98% of alerts are false | 48% false positive rate |
| Explainability | ML black boxes | 30 interpretable rules |
| Adaptability | Rigid rule thresholds | Dynamic cascaded blending |
| Precision | 2-10% | 52% |
Traditional AML systems waste compliance teams' time—up to 98% of alerts are non-fraudulent.
Our cascaded hybrid approach combines the best of both worlds: explainable rules for instant decisions, ML for pattern recognition, and adaptive blending based on risk level.
| Metric | Value | Description |
|---|---|---|
| Recall | 83.02% | Catches 83% of all fraud |
| Precision | 52.52% | Half of flagged transactions are true fraud |
| F2-Score | 74.38% | Recall-weighted performance metric |
| AUC-ROC | 89.00% | Excellent discrimination ability |
Transaction → Rule Engine → BNN Risk Check → ML Ensemble → Decision
↓ ↓
Hard Block (≥85%) Cascaded Blending
- 30 Expert Rules instantly flag high-risk patterns (5.7% hard-blocked)
- Bayesian Neural Network identifies gray-zone transactions
- 3-Model Ensemble (LightGBM 68%, XGBoost 24%, CatBoost 8%) makes final prediction
- Cascaded Blending adjusts ML/Rules weight based on risk level
cd Backend
pip install -r requirements.txt
python main.py # Runs on http://localhost:8000cd Frontend
npm install
npm run dev # Runs on http://localhost:5173cd ML_Model_Training_Files
pip install -r requirements.txt
jupyter notebook # Open the training pipeline├── Backend/ # FastAPI REST API
│ ├── main.py # /predict endpoint
│ ├── ml.py # FraudInferenceSystem
│ └── models/ # Trained ML models (.joblib)
│
├── Frontend/ # React 19 + Vite Dashboard
│ └── src/pages/ # 8 dashboard modules
│
├── ML_Model_Training_Files/ # Training notebooks
│ └── TechFiesta_2026_...Training_Pipeline.ipynb
│
├── images/ # 📸 Dashboard Screenshots
│
└── docs/ # 📖 Detailed Documentation
├── problem-statement.md # Problem & solution context
├── ml-pipeline.md # ML architecture
├── rules-engine.md # 30 fraud rules
├── api-reference.md # API docs
└── installation.md # Setup guide
| Document | Description |
|---|---|
| Problem Statement | Why this matters & our approach |
| ML Pipeline | Complete 8-step training architecture |
| Rules Engine | 30 expert rules across 9 tiers |
| API Reference | /predict endpoint documentation |
| Installation | Full setup instructions |
| Page | Route | Description |
|---|---|---|
| Command Dashboard | /command-dashboard |
Real-time monitoring |
| Detection Analytics | /detection-analytics |
Fraud trends |
| Alert Management | /alert-management-center |
Alert queue |
| Risk Scoring | /risk-scoring-engine |
Risk tools |
| Fraud Form | /fraud-detection-form |
Manual testing |
MIT License - see LICENSE for details.
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