# Refactoring while preserving behavior

Improve internal software structure in small steps while preserving observable behavior.

 Method · Technology and product


## Core concepts
  Behavior preservation: separate feature changes from structural changes
 Small steps: keep the cause of each change traceable
 Regression checks: verify existing contracts remain intact
 

## Application
 Use this approach to reduce the cost of understanding frequently changed code or prepare its structure for a new feature.


## Limitations and jurisdiction
 Preservation is difficult to judge when observable behavior and tests are unclear. Refactoring is not synonymous with a large rewrite.


## Editorial perspectives
  Incremental improvement: tidy the area around a necessary change.
 Preparation: address areas where repeated changes are costly.
 

## Sources
 Martin Fowler · Author definition page
[Refactoring](https://martinfowler.com/bliki/Refactoring.html) Context: International reference; verify the application environment
 Source checked: 2026-10-07
 Independent editorial summary and source link; the original text is not republished.


## Related personas
  [Software developer](https://personawiki.app/en/personas/developer)

## Translation status
 Editorial English translation of the Korean edition. No professional translation or occupational expert review has been completed. Translation does not change the source jurisdiction.
 Translation prepared: 2026-10-08 · Source fingerprint: kb-2c59c48839935b18
[Korean source](https://personawiki.app/knowledge/refactoring)

## API
[JSON document](https://personawiki.app/api/v1/knowledge/refactoring?lang=en)