Stop letting invalid errors exist. Build smart constructors that validate at creation time, eliminate boolean flags with traits, and simplify code through better abstractions. Real refactor from llm4s removed 263 lines and added structure.
Complete guide to building a data quality framework. Learn constraint validation in Scala, YAML checks (DPAT), Spark/Airflow/CI/CD integration, and automated failure reporting. Includes real code and architecture to catch issues early.