Ml Feature Engineering

Overview

Use this skill to design features that are useful, explainable, and consistent across training and serving.

Scope Boundaries

• Use this skill when the task matches the trigger condition described in description.
• Do not use this skill when the primary task falls outside this skill's domain.

Shared References

• Online/offline parity rules:
  • references/online-offline-parity-rules.md

Templates And Assets

• Feature specification template:
  • assets/feature-spec-template.csv

Inputs To Gather

• Candidate feature hypotheses and business rationale.
• Data sources and freshness constraints.
• Serving path capabilities and latency budget.
• Leakage/fairness/compliance constraints.

Deliverables

• Feature catalog with lineage and ownership.
• Parity validation plan for train vs serve paths.
• Feature risk and maintenance notes.

Workflow

1. Define feature specs in assets/feature-spec-template.csv.
2. Validate parity assumptions with references/online-offline-parity-rules.md.
3. Prioritize features by incremental value vs complexity.
4. Verify leakage and freshness assumptions.
5. Publish feature rollout and deprecation plan.

Quality Standard

• Feature definitions are versioned and reproducible.
• Online/offline behavior is consistent for decision-critical features.
• Feature ownership and monitoring are explicit.

Failure Conditions

• Stop when feature logic diverges between training and serving.
• Stop when feature value cannot justify operational complexity.
• Escalate when parity gaps remain unresolved.