IMPLEMENTATION: build, verify and decide
IMPLEMENTATION combines bounded agent execution with review, tests, evidence and a human decision about whether the change is acceptable. The agent's output is a draft, not a delivery; generating code is only part of the phase.
This is the fourth Core phase of AI Architect Mastery's AI Driven Development Methodology. It takes an authorized TASK and checks the result against its scope and the underlying PRD.
Why generation is not completion
A result can compile or look correct while violating a requirement or introducing architectural drift. Keep the same review discipline expected of any contributor. The methodology does not guarantee or certify production-ready software, regardless of who wrote the first draft.
Evidence ≠ an agent's completion claim. Evidence is observable information: the reviewed diff, actual test results, runtime observations and documented limitations. A confident summary or a proposed test command is not proof that the required behavior holds. Record the implementation state and environment actually checked.
What implementation review checks
- Does the actual change satisfy the TASK and stay within its scope?
- Do tests and other evidence demonstrate the required behavior?
- Does the result follow project conventions and architectural direction?
- Have security, performance, relevant edge cases and regressions been evaluated?
- Which claims remain unverified, and what risks or limitations must the human consider?
Inputs, output and responsibility
Input: an authorized TASK and its selected context. Output: a reviewed change, verification evidence and a human verdict. Owner: the agent executes within scope; the human owns evidence evaluation and acceptance.
Human Judgment and the Human Checkpoint
Human Judgment evaluates evidence against intent, constraints and acceptance criteria, including architectural direction and remaining risks. The human decides whether the observations are relevant and sufficient; passing tests do not transfer accountability to the agent.
A Human Checkpoint makes that judgment an explicit decision:
- ACCEPT
- The work meets the agreed scope and criteria with sufficient evidence.
- REVISE
- The result needs correction or additional evidence within a suitable approach.
- REJECT
- The submitted result must not progress as delivered.
- REASSIGN
- The work needs another responsibility holder, capability or execution environment.
- RETURN
- An earlier PRD, PLAN or TASK decision must be corrected before continuing.
Checkpoints are meaningful decision boundaries, not approval of every micro-action. Acceptance does not automatically authorize release or deployment; the project's separate delivery controls still apply.
Constructed example: review the whole export claim
The handler now calls the authorization helper. The reviewer inspects the diff, checks owner success and non-owner denial, and verifies that the original export format still holds. A confident summary or one successful request is insufficient evidence for that complete claim.
Illustrative evidence for example handoff E3: the following results are fictional teaching data, not tests performed on a real project.
- Scoped diff for example revision E4: handler and related tests only.
- Owner request in the example test environment: expected export returned.
- Format comparison against the example fixture: unchanged.
- Non-owner request: not executed; denial remains unverified.
Illustrative human verdict: REVISE, because E1 requires denial evidence and E4 does not establish it. Return the missing check to the bounded task and review the resulting evidence before acceptance. If the check instead exposes undefined ownership, RETURN to PRD, then refresh PLAN and TASK. Neither verdict authorizes deployment.
Explore build, verification and decisions
When to correct and when to return
A known failure within valid scope calls for correction and revalidation. If evidence exposes an earlier problem, the human chooses the return target: PRD for missing intent, constraints or acceptance criteria; PLAN for an inadequate approach; or TASK for insufficient context, scope or verification.
Pause affected execution, correct and review the earlier decision, then refresh dependent plans, assignments, context and verification. Resume under renewed human authorization and revalidate the resulting behavior and affected regressions before acceptance. An updated artifact alone does not validate downstream work, and return is not automatic routing.
Watch the IMPLEMENTATION methodology overview on YouTube (optional video; this text is the current reference).