Spec-Driven Development: A Better Way to Build with AI
AI coding tools promise speed but often deliver hallucinated code and endless rework. Spec-driven development provides the structure needed to get AI-generated code right the first time.
AI coding tools promised faster development. But as we explored in our previous post on vibe coding, they often lead to endless review cycles and rework that slow teams down instead.
The problem? The wrong tools and the wrong approach.
A new standard is emerging: Spec-Driven Development. Let’s explore what it is, why it works, and how your team can start using it today.
Why Coding Assistants Struggle with Your Business
Coding assistants are trained on public codebases and documentation. They might know how to recreate Slack or build a generic e-commerce site, because that’s all well-documented online.
But your specific business logic? Your unique workflows, compliance requirements, and domain expertise? None of that exists in any AI’s training data.
When you give an AI vague directives without clear specifications, it fills the knowledge gaps with assumptions. These assumptions are where hallucinations “breed” — and where your development cycle bogs down in endless review and rework.
Instead of building features, your developers end up wrestling with sprawling, hallucinated codebases that miss the mark.
How Spec-Driven Development Solves This
Spec-driven development doesn’t abandon the conversational nature of working with AI. It abandons the lack of structure.
It’s vibe coding with scaffolding:
- Clear requirements before you start
- Focused tasks instead of sprawling requests
- Verification steps between each chunk of work
Think of it like giving directions. Traditional vibe coding says, “get me to the airport” and hopes the AI figures out the best route. The AI might take you through every back road and wrong turn before you arrive…if you arrive at all.
With spec-driven development, you’re in the passenger seat giving one clear direction at a time. “Take exit 13…drive 20 miles north…merge onto I-85.” The AI executes each step, then waits for your next direction.
Less room for wrong turns, less hallucination.
The Four Steps of Spec-Driven Development
Most spec-driven tools, like GitHub Spec Kit, follow this framework (simplified here):
- Specify – Define what you’re building, where you’re building it, and why. This generates high-level requirements for your project or initiative.
- Plan – Detail the how: what technologies, frameworks, and architectural approaches you’ll use to build the solution.
- Tasks – Instruct the tool to break down the spec and plan into manageable chunks. For employee management functionality, for instance, it would create separate tasks for each CRUD operation (create, read, update, delete) instead of one massive “build the whole thing” directive.
- Implement – Ask the coding assistant to implement these tasks one at a time, and it will do so based on the functional and non-functional requirements you’ve outlined.
In GitHub Spec Kit, these steps are executed through three sequential slash commands:
/specify, /plan, and /tasks
These commands guide the AI through each phase. Once you’re satisfied with the outputs, you simply ask your coding assistant to implement the project.
Important: Spec-driven development can consume significant credits quickly since most AI coding assistants charge based on tokens processed per interaction. Taking time to review your specifications, planning, and task breakdown ensures both correctness and cost efficiency.
Ready to Try It?
We use GitHub Spec Kit for spec-driven development. It integrates directly with GitHub workflows and provides the complete spec-to-code capabilities we covered above.
Other tools include:
- Kiro – Focuses on AI-native development with built-in validation and testing frameworks.
- Tessl Framework – An open-source approach that emphasizes modular specifications and incremental implementation.
The tools are ready. The challenge? Shifting your team’s mindset from ad-hoc prompting to structured specification.
What Relevantz Can Do for You
Our engineering team has hands-on experience implementing spec-driven development practices. We can build a project with you using this methodology — showing you what’s possible with your actual codebase and business requirements.
Ready to actually accelerate development? Contact us to schedule a complimentary consulting session.