Family reworks follow data-oriented design

Rework each instrument family with the data-oriented approach. Organise the tables by how the code reads and writes the data together, not by the product taxonomy. Key every row by its trade. Hold a list as rows of a child table. State the variation as a header with one fact table per product. Review the design with the data-model review skill before any model is written.

Why: The bond pilot and the rates rework both came from this method. The wide credit table, with 25 columns for eight codes, is what the taxonomy approach produces.

How to apply: Before a family rework, read doc/knowledge/architecture/data_oriented_design.org, state the regime (persisted domain data), and write the analysis as findings with evidence before any model. Follow the family rework runbook.