Specs-Driven vs Prompts-Driven: Thoughts From Recent Chats With Builders
Hey folks — Ryan here
I’ve been chatting with a bunch of vibe-coding builders lately, and everyone keeps saying the same thing:
Prompts get you UI fast — but the moment things get real, everything starts to fall apart.
they told me:
“I’m rewriting prompts all day because the logic drifts.”
“Looks good, but the flow makes no sense.”
“I’m vibe-coding… but also vibe-debugging.” 😅
And it hit me:
Prompts give you speed.
Specs give you control.
You need both, but right now most tools only give you the first one.
When products get states, rules, edge cases, handoffs…
prompt-driven workflows just break.
Context gets lost, UI and logic go out of sync, agents reinvent things, nothing stays aligned.
So I started asking myself:
What if vibe-coding was specs-driven, not prompts-driven?
What if structure — not prompts — was the real foundation?
That’s the direction my team and I have been exploring:
an AI PM + AI Designer working together on one canvas,
keeping richer specs (PRDs, flows, UI, and prototypes) aligned while you build.
Curious how you all deal with this:
Where does your vibe coding usually lose control?
Do you write specs first, or go straight into prompting?
What kind of structure would make your builds more stable?
Would love to hear your experiences
Replies
I run a small AI heavy agency and I see the same pattern every time. Prompts get you moving fast, but the moment a project gets states, branching or multiple agents, everything drifts. Logic breaks, UI goes rogue, and you spend the day fixing vibe instead of building.
Lately I flipped the workflow. Before prompting, we define a lightweight structure: core logic, states and transitions, simple PRD. Nothing fancy, just enough to stop the AI from wandering. The output is less magical but far more stable.
What you’re exploring makes real sense. We don’t need another screen generator. We need a system that keeps specs as the single source of truth and aligns design and logic as you build.
Curious what you see as the minimum structure to keep things stable
State model
Flow
Constraints
All of it?
Vibe coding is moving to spec driven approach if you follow recent launches from AWS Kiro, Google Antigravity. I personally prefer context driven development. Where context is spec/roadmap + existing state of code + any specialized knowledge not part of model's knowledge cutoff + custom tools required to augment a development task. So I end up spending good amount of time crafting my context = skills, commands, memory, tools, backlog - most if it is reusable across the project iterations and across many projects over time.