Use when a reviewed task slice has tests or acceptance targets and the team must turn it into a small, mergeable implementation increment without expanding scope, breaking contracts, or hiding release-boundary risk.
Implement the next reviewed slice as a small, test-backed increment that can be reviewed and delivered safely.
Feature development is where plans become working behavior. In Prodcraft, it sits between test-first design and formal review: the task is not "write a lot of code," but "land the smallest useful slice that satisfies the current plan and keeps downstream delivery safe."
This skill is especially important when the architecture, contract, and release boundary are already known. It prevents implementation from drifting into hidden scope expansion, accidental product decisions, or broad rewrites disguised as progress.
Choose one reviewed task or thin vertical slice. Rewrite it in concrete implementation terms: what behavior lands now, what stays out of scope, and what boundary must remain stable.
If the slice is still too large to review comfortably, split it before coding.
Use the failing or targeted tests as the implementation guardrail. Add only the code needed to satisfy the current slice. Keep new abstractions local until a second use proves they belong.
Prefer vertical progress over partial framework setup. A small end-to-end slice is more valuable than three half-finished layers.
Before each commit or reviewable checkpoint, verify:
Clean up obvious naming, dead code, and accidental noise that would distract review, but do not turn implementation into a refactoring detour. The output should be a small, understandable diff with passing tests and explicit notes on any trade-offs.
skills/.curatedskills/04-implementation/feature-development/SKILL.mdnpx skills add/update compatibility.betabeta