Lecture 08. Specs, locked tests and layer rules as delivery gates

Part 3 · The Harness as a Control Layer · Scheduled 27 Dec 2026 · 1-hour lecture

Upcoming course outline. This class has not been recorded as studied.

Learning objectives

• Verification separates vibe coding from agentic engineering (Day 1 pp. 12-15).
• Spec as source of truth; Gherkin; the four-part spec (Day 5 pp. 7-9); size the spec to the task (Kiro: 16 criteria for a small bug).
• 'Use TDD' fails: faked red step, 3-8.5x tokens (Böckeler); human-owned tests; red gate; mutation score.
• Test/code separation (Day 4 p. 23) vs self-written tests (Day 5 p. 29); repro test first for bugs (Day 5 pp. 13-14).
• Layer rules in ARCHITECTURE.md and an import-linter gate: a patch can pass every test and still break the architecture; brownfield zones (green, yellow, red) set what the agent may touch.

Why this class matters

• Industry: Spec, tests, CI and review are the daily workflow with coding agents; this is the class a hiring manager asks about.
• Academic: Spec vs free-form runs across all pairs form a real experiment with pooled data.
• Elsewhere: Students write specs that a human and a model both read the same way.

Preparation requirements

• Google Day 1, Day 4, Day 5 2026 (Day 5 pp. 7-15 pre-reading).
• Böckeler, TDD in the agent loop and SDD; Kiro specs; spec-kit README.
• Claude Code docs: hooks, permissions, sandboxing.

These are preparation requirements in the draft; staff materials are not bundled with this site.

Preparation and readings

• Google/Kaggle 2026, Day 1: The New SDLC With Vibe Coding
• Google/Kaggle 2026, Day 4: Vibe Coding Agent Security and Evaluation
• Google/Kaggle 2026, Day 5: Spec-Driven Production Grade Development
• Böckeler: TDD inside the agent loop (martinfowler.com)
• Kiro docs: specs
• Claude Code docs: hooks
• Claude Code docs: permissions
• Claude Code docs: sandboxing

The linked reference library contains the source URLs extracted from the course PDF. Availability notes above reflect the draft of 4 November 2026.

Paired lab

Continue with Lab 08: Specs, locked tests and layer rules as delivery gates. Every lab contributes an artifact to the same repository and a measurement to the results ledger.

Personal notes

[Lecture notes and observations]