# Step 4: Cross-Task Verification (implementation and tests-only modes)

**Role**: Professional software architect and analyst
**Goal**: Verify task consistency and produce `_dependencies_table.md`.
**Constraints**: Review step — fix gaps found, do not add new tasks.

## Steps

1. Verify task dependencies across all tasks are consistent
2. Check no gaps:
   - In implementation mode: every product interface in `architecture.md` has implementation task coverage
   - In tests-only mode: every test scenario in `traceability-matrix.md` is covered by a task
   - In implementation mode: every named internal runtime capability/dependency from architecture, solution, system flows, and component descriptions has a production implementation task, not only an interface/scaffold/fallback task
   - In tests-only mode: every e2e/blackbox task has a System Under Test Boundary section that forbids stubbing internal product modules and requires comparison to expected-results artifacts
3. Check no overlaps: tasks don't duplicate work
4. Check no circular dependencies in the task graph
5. Produce `_dependencies_table.md` using `templates/dependencies-table.md`

## Self-verification

### Implementation mode

- [ ] Every product interface in `architecture.md` is covered by at least one implementation task
- [ ] Every named internal runtime capability has a production implementation task
- [ ] No circular dependencies in the task graph
- [ ] Cross-component dependencies are explicitly noted in affected task specs
- [ ] `_dependencies_table.md` contains every task with correct dependencies

### Tests-only mode

- [ ] Every test scenario from `traceability-matrix.md` "Covered" entries has a corresponding task
- [ ] Every e2e/blackbox task validates actual product behavior and allows stubs only for external systems
- [ ] No circular dependencies in the task graph
- [ ] Test task dependencies reference the test infrastructure bootstrap
- [ ] `_dependencies_table.md` contains every task with correct dependencies

## Save action

Write `_dependencies_table.md`.

## Blocking

**BLOCKING**: Present dependency summary to user. Do NOT proceed until user confirms.