What One Iteration Costs

Description and use

A defined and automated approach to measuring the cost of a single code iteration tracks tests-to-code ratio and average file size, enabling early defect detection and growth control.

Problem

Estimating the time and token cost of a single code iteration in a PHP monolith migrating to Go services.

Outcome

Clear, repeatable measurement of iteration cost enabled early warning of quality regressions and informed consolidation releases, improving code-test balance and growth strategy.

Workflow

• Define iteration unit as executor work on one iteration
• Exclude prompt writing, review, CI wait, and generated code from metrics
• Run scripted commands to count code lines, test lines, files, packages
• Generate tag-to-tag table automatically on each new tag
• Monitor tests-to-code ratio and average file size as quality gates
• Use metrics to validate consolidation releases and growth patterns

Evidence

An estimate is the working time of one background executor on one iteration: editing the named files, moving and extending the tests, running them until green.

Source

The tests-to-code ratio is the row I actually watch.

Source

The document is regenerated on every new tag and on the close of any large prompt set.

Source