The Prototype Is Done. What's Left to Design?
Prototypes are the new design briefs and 7 tips for designers on how to spot hidden assumptions and turn a demo into a clear product direction.
Your clients or managers (non-designers) now show up with working prototypes.
They look close to done, and the reflex is to wonder what is left for you to do.
In the past you had wireframes that allowed you to control the order decisions got made.
You showed structure first, then flow, then detail, so people could settle one thing at a time while the rest stayed open.
Today, we have finished-looking prototypes. Every decision arrives at once and feels settled because people can already interact with it. Ah, and it looks polished, and they might be already attached to it!
So what's left for YOU to do?
The Prototype Is the New Brief
AI turns a rough idea into something functional in minutes. Your client or manager can finally see their own thinking, tweak it, and show it around. The prototype is how they communicate now, and it puts them one step ahead of a written brief.
Most of the time the purpose of the prototype is to get feedback and momentum.
The prototype becomes a conversation starter.
When someone sends you a vibe-coded prototype, do not start with visual critique.
Start with questions:
What were they trying to figure out?
What part feels important to them?
What part are they unsure about?
Understand what role it is supposed to play.
7 Tips for Reviewing Vibe-Coded Prototypes!
Instead of reviewing it like a finished design, review it like a new kind of brief:
Chase the goal.
Start with the reason it was made. Was it meant to test an idea, explain a feature, align a team, pitch a concept, or move into production?Map the scope.
Make the invisible edges visible. What does the prototype cover, what does it skip, and what would still need to exist in the real product?Spot the tool’s fingerprints.
Not everything in the prototype was a real decision. Look for default layouts, generic copy, familiar components, and interaction patterns that may have been generated rather than chosen.Trace the decisions.
A working prototype can make unfinished thinking feel settled. Follow each major choice back to a reason before the team treats it as final.Look past the pixels.
Do not let polish distract you. Check whether the flow solves the right problem, supports the user, and holds up beyond the happy path.Stay open to alternatives.
Treat it as one possible direction, not the answer. Think about and explore other ways things could work.Check it against what exists.
Hold the prototype up to the requirements, specs, or the design system already in place.
Taking It Further
Depending on the project, your next job might be to:
Extract the scope and take it further.
Facilitate conversations around the prototype to reach a shared understanding.
Make sure it respects an existing design system or brand direction.
Prepare it for development, with the full set of use cases and states.
Take it further and build the final front end.
Ensure it meets accessibility, AI, and UX standards.
Put it in front of real people, run the research, and capture feedback.
Add the layer of polish: haptics, motion, micro interactions, animations.
Define the UX metrics, so the team knows what success looks like.
Add your magic: creativity, craft, and a your point of view! 🪄
When someone can already bring a clickable version, they’re asking you to make sense of what exists, question what it assumes, and help the team decide what should happen next.
I hope this gives you a clearer way to look at the next prototype that lands on your desk. If you have run into this already, I would love to hear your story or tips.
Thanks for reading! 🫶
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I’m Ileana Marcut, founder of Creative Glue Lab, a design + development studio focused on digital products, AI-native tools, and systems. I write UX+AI, where I share practical insights at the intersection of UX, AI, and product strategy.
This is great, I think in terms of looking past the pixels. Agents like Claude have a tendency to overinflated things, so this step of assessing that is really important!