Guide

Vibe Coding vs Spec-Driven PM

Vibe coding gives you velocity. Spec-driven product management gives you direction. Here is when to use each - and how to combine them for AI-native product development.

The rise of vibe coding

In early 2025, Andrej Karpathy coined the term “vibe coding” - the practice of prompting AI coding agents conversationally, iterating on output in real-time, and letting the agent handle implementation details. You describe what you want. The agent builds it. You refine by feel.

It works remarkably well for exploration. Engineers can prototype in minutes what used to take days. Internal tools, proof-of-concepts, and hackathon projects ship at unprecedented speed.

But vibe coding has a ceiling. When you move from “can we build this?” to “should we build this, and does it connect to our strategy?” - conversational prompts are not enough. You need structure. You need specifications.

The vibe coding trap

Building is now cheap. But building the wrong thing fast is still expensive. Teams that vibe-code production features report 40-60% rework rates because the agent built something that works technically but misses the strategic intent.

Side-by-side comparison

Different tools for different jobs. Neither is universally better.

Dimension
Vibe Coding
Spec-Driven PM
Who leads?
Engineer
Product manager
Input to agent
Conversational prompts
Structured specification
Strategic context
Optional (often absent)
Embedded in spec
Iteration speed
Minutes
Hours (but correct)
Quality driver
Developer judgment
Spec quality + guardrails
Best for
Exploration, prototypes
Production features
Learning loop
None (disposable)
Captured in system
Scales to team?
Solo only
Cross-functional teams

When to use each approach

Vibe coding is great for...

  • -Prototyping a concept to validate feasibility
  • -Hackathons and time-boxed experiments
  • -Internal tools only your team uses
  • -Technical spikes exploring a new API or library
  • -Personal projects and side projects
  • -Early exploration before you know what to build

Spec-driven PM is for...

  • Customer-facing features with quality expectations
  • Cross-team work requiring shared understanding
  • Features connected to OKRs and strategic goals
  • Anything that needs to be maintained long-term
  • Work that will be reviewed, measured, or audited
  • When multiple agents or engineers touch the same area

The hybrid approach: explore, then specify

The best AI-native teams do not choose one approach exclusively. They use both in sequence:

1. Explore

Vibe-code prototypes to validate feasibility and discover constraints. Throw away the code - keep the learnings.

2. Specify

Write a structured spec that captures what you learned. Include vision context, guardrails, and success criteria.

3. Ship

Hand the spec to an AI coding agent for production implementation. The spec ensures strategic alignment at scale.

This is not a rigid waterfall. The explore phase might take 30 minutes. But the spec captures intent in a way that conversational prompts cannot - especially when multiple people, agents, or sprints are involved.

Why product management matters more - not less - when building is cheap

The common narrative is that AI coding agents will replace product managers. The reality is the opposite. When building is cheap, the constraint shifts from “can we build this?” to “should we build this?”

Vibe coding makes it trivial to build features. But without product context - vision, strategy, OKRs, discovery insights, competitive positioning - you ship features that nobody asked for, that conflict with your strategy, or that duplicate existing capabilities.

Spec-driven product management is how PMs stay relevant in the AI-native era. Not by writing code. Not by managing tickets. By maintaining the strategic context that makes AI agents build the right thing - not just the next thing. As Marty Cagan argues, foundation models become effective product coaches only when given your company’s strategic context — read the full analysis.

The learning loop

In vibe coding, learnings disappear when you close the chat window. In spec-driven PM, every cycle improves the specification system - learning captures feed back into vision, strategy, and future specs. Your product gets smarter over time.

Ready to move from vibes to specs?

Delvyn Studio is purpose-built for spec-driven product management. Connect your vision to your specifications - then hand them off to AI coding agents.