Vibe Coding vs Spec-Driven Development

Category: Context Engineering Approaches Last updated: December 28, 2025

Overview

In AI-assisted development, two distinct approaches have emerged: vibe coding and spec-driven development. Understanding the difference between these approaches is crucial for choosing the right workflow for your team and project.

Vibe coding is an informal, conversational approach where developers iteratively guide AI agents through natural language prompts, refining outputs through back-and-forth dialogue until the implementation "feels right."

Spec-driven development (SDD) is a structured approach where developers first create explicit specifications defining requirements and expected behavior, then use these specs to guide AI implementation and validate outputs.

This is a curated summary from the comprehensive analysis. Read the full comparison →

Vibe Coding Workflow

The vibe coding workflow follows an iterative, exploratory pattern:

  1. Describe what you want: Provide a natural language description of the desired feature
  2. AI generates code: The AI agent produces an initial implementation
  3. Review and adjust: You test the output and provide feedback
  4. Iterate: Back-and-forth refinement continues until the result feels acceptable
  5. Move forward: Once satisfied, move on to the next feature

This approach works well for quick prototypes, exploration, and when requirements are truly unclear. However, it's prone to intent-to-implementation drift—gradual divergence between what you actually wanted and what got built.

Spec-Driven Development Workflow

SDD follows a more structured pattern:

  1. Write specifications: Create structured specs defining requirements, scenarios, and acceptance criteria
  2. Review specs: Validate that specs capture your actual intent (cheaper to fix here than in code)
  3. AI generates code: AI implements based on clear, explicit specifications
  4. Validate against specs: Verify implementation matches specification requirements
  5. Update specs: Keep specifications synchronized as the system evolves

This approach frontloads clarity, making intent explicit before implementation begins. While it requires more upfront work, it reduces costly rework and maintains alignment over time.

Intent Alignment & Drift Management

Vibe Coding: Reactive Drift Management

In vibe coding, drift is managed reactively. When you notice the implementation diverging from your intent, you course-correct through additional prompts. This works initially but becomes increasingly difficult as the codebase grows and interactions between features become complex.

The challenge: without an explicit reference point, it's hard to know if subtle drift has occurred until it causes problems.

SDD: Proactive Drift Prevention

SDD prevents drift by maintaining specifications as the source of truth. When implementation diverges from specs, it's immediately visible. You can validate at any time by comparing code behavior against specification requirements.

The specification serves as a "contract" that both humans and AI agents can reference, making deviations obvious before they compound into larger problems.

When to Use Each Approach

Use Vibe Coding For:

Use Spec-Driven Development For:

Hybrid Approach

Many teams use both: vibe coding for initial exploration and prototyping, then transition to SDD for production implementation. This combines the speed of vibe coding with the rigor of SDD.

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