This curriculum spans the breadth of a multi-workshop program on machine learning operations, addressing the technical, governance, and lifecycle management challenges teams encounter when deploying and maintaining feature selection practices in production business systems.
Module 1: Defining Business Objectives and Aligning Feature Selection Goals
- Selecting target variables based on measurable business KPIs such as customer churn rate or average order value, rather than model accuracy alone.
- Mapping predictive modeling goals to operational decisions, such as determining whether a model will support real-time scoring or batch risk assessment.
- Identifying data latency constraints by evaluating whether near-real-time features (e.g., last login time) are feasible given source system update cycles.
- Deciding between global versus segmented models based on business unit requirements, which affects feature relevance across customer cohorts.
- Establishing thresholds for model interpretability when compliance or stakeholder communication requires clear feature impact explanations.
- Documenting feature lifecycle ownership to clarify accountability for updates when business logic changes (e.g., new product categories).
Module 2: Data Inventory and Feature Readiness Assessment
- Conducting a lineage audit to trace each candidate feature from source system to warehouse, identifying transformation points that may introduce bias.
- Assessing feature availability at prediction time by verifying whether variables like credit score are accessible during live inference.
- Quantifying missing data patterns across features to determine imputation feasibility or exclusion (e.g., 60% missing income data in CRM).
- Evaluating feature update frequency against model refresh cycles to avoid stale inputs in production (e.g., monthly billing data in a daily model).
- Flagging features derived from manual entry or third-party APIs that introduce operational fragility and monitoring overhead.
- Classifying features by data type and scale to inform preprocessing requirements (e.g., log-transforming monetary amounts).
Module 3: Statistical and Correlation-Based Filtering
- Applying variance thresholds to remove near-constant features (e.g., 99.5% zero values in promotional flag fields).
- Using pairwise correlation matrices to detect redundant features, such as multiple tenure measures from overlapping date fields.
- Implementing ANOVA F-tests to evaluate the significance of categorical features against continuous targets in regression tasks.
- Excluding features with high correlation to the target in time-series settings to prevent look-ahead bias (e.g., next-month balance used as input).
- Adjusting p-value thresholds based on multiple testing corrections when screening thousands of features simultaneously.
- Retaining theoretically important features despite low statistical scores when domain knowledge suggests delayed or nonlinear effects.
Module 4: Model-Driven Feature Importance and Wrapper Methods
- Running recursive feature elimination with cross-validation to identify minimal feature sets that maintain performance on validation folds.
- Comparing permutation importance across models (e.g., Random Forest vs. XGBoost) to assess stability of feature rankings.
- Configuring early stopping in iterative selection to avoid overfitting during nested cross-validation loops.
- Monitoring computational cost when applying wrapper methods to high-cardinality datasets, limiting candidate features to 500 for feasibility.
- Interpreting SHAP values to detect interactions (e.g., age and income) that justify retaining both features despite moderate individual importance.
- Documenting the performance delta between full and reduced models to justify selection decisions to technical stakeholders.
Module 5: Handling Multicollinearity and Feature Engineering Trade-offs
- Calculating variance inflation factors (VIF) to identify and remove collinear features in linear models affecting coefficient stability.
- Deciding whether to keep original features or principal components based on stakeholder interpretability requirements.
- Managing the risk of over-engineering by capping the number of derived features per source variable (e.g., no more than three lag features).
- Validating engineered features against business logic, such as ensuring rolling averages align with operational reporting periods.
- Tracking feature creation dates and dependencies to support debugging when model performance degrades.
- Using domain-specific transformations (e.g., RFM scoring) only when historical analysis confirms predictive lift.
Module 6: Operational Constraints and Production Readiness
- Enforcing feature schema validation in the inference pipeline to prevent model errors from unexpected nulls or type changes.
- Designing fallback logic for missing features during scoring, such as using cohort averages when individual values are unavailable.
- Implementing feature versioning to support A/B testing and rollback capabilities in production environments.
- Measuring feature computation latency to ensure real-time models meet SLAs (e.g., sub-100ms feature extraction).
- Registering features in a central catalog with metadata including ownership, update frequency, and business definition.
- Setting up monitoring for feature distribution drift using statistical tests (e.g., Kolmogorov-Smirnov) on weekly batches.
Module 7: Governance, Compliance, and Ethical Considerations
- Screening features for protected attributes or proxies (e.g., ZIP code as a race surrogate) to comply with fair lending regulations.
- Documenting data provenance for audit purposes, especially when features originate from third-party vendors.
- Implementing role-based access controls on feature stores to restrict sensitive data (e.g., health indicators) to authorized teams.
- Conducting bias audits by stratifying model performance across demographic groups defined by available features.
- Archiving deprecated features with retention policies aligned to legal and compliance requirements.
- Requiring change control approvals for modifications to high-impact features used in regulated decisioning systems.
Module 8: Iterative Refinement and Monitoring in Live Systems
- Scheduling quarterly re-evaluation of feature importance to detect decay due to market or behavioral shifts.
- Integrating feature performance metrics (e.g., AUC drop when removed) into model monitoring dashboards.
- Triggering retraining pipelines when feature availability drops below 95% in production data streams.
- Using shadow mode deployments to test new features without impacting live decisions or customer experiences.
- Logging feature values alongside predictions to enable post-hoc analysis of model behavior in edge cases.
- Establishing feedback loops from business units to report when model outputs contradict observed trends, prompting feature review.