incremental-implementation

Break the feature into thin vertical slices where each slice delivers working end-to-end functionality. After each slice, run the test suite and build, verify the result, and commit before starting the next slice.

Vertical slicing builds one complete path through the stack per increment, such as database plus API plus UI for a single operation. Each slice leaves the system in a working, testable state rather than completing one layer at a time.

Use feature flags when a feature is not ready for users but you need to merge increments to the main branch. Gate the new code behind an environment variable so incomplete work stays hidden while small increments merge safely.

Skip it for single-file, single-function changes where the scope is already minimal. The overhead of slicing only pays off when a change touches multiple files or exceeds roughly 100 lines before testing.

A bug introduced in an early slice silently corrupts every slice built on top of it, making the root cause hard to locate among hundreds of changed lines. Testing each slice isolates failures to the most recent change.