DELIVER
The DELIVER phase implements working code, guided by tests, with empirically verified quality.
What enters, what exits
| Comes from | DISTILL — the Gherkin scenarios + the plan |
| What enters | Executable specifications to implement |
| What exits | Tested code + quality evidence (mutation, RED→GREEN) |
| Goes to | The Pull Request — human review then delivery |
| Responsible agent | software-engineer |
| Associated reviewer | software-engineer-reviewer |
Why this phase exists
Code is the only artefact that matters in production. The software-engineer applies Outside-In TDD: Acceptance Tests guide unit tests, which guide implementation. The Mutation Score verifies that tests genuinely protect behaviour. The reviewer is read-only — it never modifies code.
« We grow working software, guided by tests, from the outside in. » — Freeman, S. & Pryce, N., Growing Object-Oriented Software, Guided by Tests, 2009.
☕ Running example — Starbucks (illustrative)
The scenario enters. DELIVER implements the total calculation and loyalty crediting in RED → GREEN cycles, then a mutation score attests that the tests genuinely protect the loyalty rule. The code goes to a Pull Request.
What the agent produces
- Code implemented following the RED → GREEN → REFACTOR cycle.
- Passing acceptance tests linked to Gherkin scenarios.
- Unit tests covering Domain invariants.
- Mutation Score as empirical proof of test quality.
The internal fan-out: test wiring
The software-engineer does not wire the integration tests by hand: it delegates
that wiring to internal subagents (user-invocable: false), one per capability.
| Capability | Worker | Strategy | Fidelity lens |
|---|---|---|---|
| Mocking (consumer) | mock-integration-worker |
Microcks by default, overridable in-process | mock-fidelity-lens |
| Contract (provider) | contract-testing-worker |
in-process integration + Microcks opt-in | contract-fidelity-lens |
Each worker emits test wiring only — the business TDD cycle stays with the lead, who
verifies the worker in TIER-1 (the test fails first, then passes). When a
capability is active, its fidelity lens joins the adversarial panel of the
software-engineer-reviewer. The concrete wiring is resolved per stack through a
roster (see the skills).
Gates crossed here
This phase crosses the delivery gates — RED/GREEN test integrity, green build, mutation score at threshold (see the gates catalogue). The independent reviewer issues its verdict before the PR is opened.