ML Data Pipeline Architecture Patterns for efficient ML data pipelines using Polars, Arrow, and ClickHouse. ADR : 2026-01-22-polars-preference-hook (efficiency preferences framework) Note : A PreToolUse hook enforces Polars preference. To use Pandas, add at file top. Self-Evolving Skill : This skill improves through use. If instructions are wrong, parameters drifted, or a workaround was needed — fix this file immediately, don't defer. Only update for real, reproducible issues. When to Use This Skill Use this skill when: - Deciding between Polars and Pandas for a data pipeline - Optimizing mem…