Design a comprehensive predictive modeling solution for a complex scenario (such as customer churn prediction in a subscription service, housing price estimation in volatile markets, or demand forecasting for a seasonal product). Your response should include: 1) Feature engineering methodology with justification for each variable selection, 2) Comparison of at least three different modeling approaches with explanation of trade-offs, 3) Validation strategy addressing potential data leakage and temporal dependencies, 4) Interpretation techniques for model explainability, 5) Deployment considerations for real-time inference, and 6) Monitoring approach for model performance degradation.