Phase 3: The Generate-Validate Loop · 45 min · Claude Code · Python

The Validate Phase: Beyond "It Works"

"The AI said it's done" is not validation. Neither is "it ran without crashing."

Real-world application: Naming the specific red flags in a code review — not a vague 'looks fine to me' — is exactly what distinguishes an engineer who validates AI-generated code from one who's just reading it for vibes.

What you will learn

Explain why an agent's self-report that code 'works' is not validation
Distinguish functional checkpoints (does it run) from acceptance validation (does it meet the spec)
Identify the four AI-generated code red flags: hardcoded secrets, swallowed errors, magic numbers, sycophantic comments
Build a static scanner that catches these red flags automatically instead of relying on manual review alone

Introduction

The Validate Phase: Beyond "It Works"

Objective

Statically scan Python source for the four red flags this lesson names: hardcoded secrets, swallowed errors, magic numbers, and sycophantic comments.

Unlock the full lesson

You've read the first 2 sections. The rest of this lesson covers The Problem, The Concept, Build, Check Yourself, Key Terms & Next — plus a hands-on lab, quiz, and project artifact.

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Key terms in this lesson

Agent