Why Spec Coding Beats Vibe Coding: Proven Practices for AI‑Assisted Development

Background

In 2025 the AI‑assisted programming field experienced several rapid milestones. Andrej Karpathy introduced Vibe Coding , a concept where developers describe desired functionality without writing code, aiming to lower the entry barrier for non‑programmers. However, the approach faces challenges in real‑world enterprise projects due to hidden information gaps, proprietary frameworks, and stability concerns.

Spec Coding vs. Vibe Coding

At AIEWF 2025, OpenAI researcher Sean Grove argued that a Spec (specification) is more important than raw code. He likened a high‑level language to source code and AI to the compiler: a Spec can be fed to AI to generate code on demand. Compared with Vibe Coding, Spec Coding is better suited for production environments because engineers can review and refine the Spec before AI generates code, improving controllability and reducing stability risks.

Context Engineering and Skill

In June 2025 the term Context Engineering emerged, shifting focus from prompt phrasing to providing the model with the right background knowledge. Five best‑practice patterns were identified:

State Management – using todo‑list‑style agents.

Progressive Context – gradually enriching context through queries and concept extraction.

Structured Output – enforcing structured formats for queries and specs.

Template Programs – reusable prompts for sub‑tasks (subagents, skills).

Multi‑step Processing – decomposing complex tasks into workflows.

Anthropic later introduced the Skill concept, which implements progressive context by listing skill names and brief descriptions in the initial prompt and expanding each skill’s details as needed. Skills keep context in the main flow, whereas Subagents have isolated context spaces.

Challenges When Using Skills for AI Coding

Complex tasks make a single Skill overly complicated, requiring decomposition.

Multiple Skills can lead to low execution accuracy without proper guidance.

Crafting high‑quality Skills is time‑consuming.

Introducing kuspec: A Workflow‑Based Solution

The internal tool kuspec addresses the above challenges:

Defines a Workflow as an ordered collection of single‑responsibility Skills, breaking complex tasks into clear steps.

Provides commands to create Workflows and Skills quickly.

Workflow Structure

A Workflow consists of two files in a directory: WORKFLOW.md – describes business context and Skill orchestration. WORKFLOW_INIT.md (optional) – performs complex initialization, such as generating a structured document for user input before the main workflow runs.

Example images illustrate the file layout and repository structure.

Workflow Repository (WorkflowRepo)

Workflows and their Skills are stored in a Git repository (WorkflowRepo), enabling versioned iteration and team sharing. The repo contains a config.json and multiple Workflow directories.

Integrating Workflows into an Agent

Custom commands are added to an Agent via MCP (Model‑Centric Platform) to invoke Workflows: /kuspec:init The init command runs the WORKFLOW_INIT.md script, prompting the user for required information. /kuspec:execute The execute command retrieves the selected Workflow’s WORKFLOW.md, resolves required Skills through MCP, and runs the steps sequentially.

Practical Application Scenarios

Plugin or module development within specific frameworks – automates repetitive template creation.

Front‑end UI redesign or server‑side CRUD tasks – leverages design‑tool MCPs to supply UI context.

Small‑team “niche” tech stacks – encapsulates expert knowledge into reusable Workflows for broader team adoption.

Cross‑team integration – packages service or SDK onboarding procedures as Workflows, reducing inter‑team coordination overhead.

Final Thoughts

Current AI capabilities are still insufficient to independently manage large‑scale projects; AI functions best as an engineer’s assistant. Embracing AI to automate repetitive work frees developers to focus on higher‑value tasks, ultimately delivering greater business impact.