For Technical Startup Founders Working with a UX/Product Designer
Introduction
If you’re a technical founder at an early-stage startup, chances are you’ve got a big vision and a tight runway. You’ve probably hired a freelance product designer or a UX/UI designer to help bring your idea to life. But here’s a common disconnect: instead of sharing the problem you’re solving, you hand over a wishlist of design elements — "put a dropdown here," "make this a modal," "use blue."
This guide is here to help you write better product requirements — the kind that unlock smarter, faster work from your team, especially your product designer. Whether you're building a v1, running a design sprint, or looking for rapid prototyping, this is your playbook.
The Three Types of Requirements (and Why Founders Get Stuck)
High-level summary:
- Product requirements define the user problem and business goal.
- Design requirements guide how the user experiences the solution.
- Engineering requirements cover the technical constraints and backend realities.
1. Product Requirements
These are your source of truth. A good product requirement tells us:
- What problem you're solving
- Who you're solving it for
- Why it matters
Instead of saying, “Add a dashboard,” say, “Sales reps need a quick way to understand their daily pipeline so they can prioritize outreach.”
This clarity is gold for a product designer. It creates space for better ideas while keeping the focus on the user’s pain. It’s especially critical when designing for an MVP, where scope is everything.
2. Design Requirements
This is where a UX/UI designer starts translating your goals into a user journey. Design requirements should describe:
- What the experience needs to achieve
- Any brand constraints (colors, tone, accessibility)
- The desired emotional or behavioral response
Bad: “Use a modal to show onboarding.”Better: “First-time users should understand core functionality in under 2 minutes, without reading help docs.”
You hired a product designer to make these calls — don’t micromanage the layout. Define the outcome, and trust their process.
3. Engineering Requirements
Once the product and design directions are clear, engineering requirements make it real. These requirements handle:
- Platform-specific details (e.g. iOS 17, WebGL, etc.)
- Performance expectations (e.g. load time under 2s)
- Data and security requirements
These typically live in technical specs, but your product requirements must anticipate them. That’s why collaboration between design, product, and engineering early on is key.
Best Practices for Writing Startup-Friendly Product Requirements
High-level summary:
- Focus on the problem, not the solution.
- Write from the user’s perspective.
- Collaborate with your designer and developer.
- Leave room for innovation.
- Avoid over-detailing or vague buzzwords.
Focus on the Problem
You’re not hiring a UX designer to be a wireframe robot. You want someone who knows how to solve product problems visually. Instead of telling them "Make it look like Notion," say, "Users need a way to capture notes quickly without leaving their workflow."
Write User Stories
Use the classic formula: As a [user type], I want to [action], so that [goal].
Example:
As a team lead, I want to assign tasks in bulk, so that I can onboard new projects faster.
This gives your product designer a lot more to work with than “Add a bulk action button.”
Collaborate Early
Great outcomes happen when everyone is aligned from day one. If you’re working with a product designer or doing user research, bring in your team early. Share your findings. Talk through technical trade-offs together.
At Serif Labs, we embed deeply with your team — not just to design, but to shape the product direction alongside you.
Leave Room for Creativity
Let your product designer explore different directions. Say what success looks like, not how to get there. That’s how we unlock simple, elegant solutions that no one thought of yet.
Bad: “Use three tabs at the top.”
Better: “Users need a way to switch between views without losing their place.”
Avoid the Buzzwords
“Easy to use.” “User-friendly.” “Intuitive.” These don’t mean anything unless you define them.
Instead of “intuitive onboarding,” say: “New users should complete setup in under 3 minutes with no support.” Now it’s testable.
Real-World Case Studies
Case Study 1: Vague vs. Clear
Bad: “It should have good UX.”
Better: “First-time users should complete sign-up in under 2 minutes on mobile.”
Impact: Clearer goals led to simpler flows and faster onboarding.
Case Study 2: Over-Specified Design
Bad: “Use a 500px modal for onboarding.”
Better: “On first login, guide users through key features without blocking the main UI.”
Impact: The designer created a guided tooltip flow instead — more elegant, and better conversion.
Case Study 3: Feature vs. Benefit
Bad: “Add a reporting page.”
Better: “As a founder, I want to see user growth by week so I can measure traction.”
Impact: Focused design effort on the right metrics, not vanity charts.
Why This Matters
This really is the secret to building faster and smarter:
- You reduce rework by getting aligned early.
- You build the right thing, not just something flashy.
- You get more value out of your MVP.
- You actually design for the user — not just what’s trendy.
Clear product requirements lead to better software, tighter team collaboration, and happier users. If you're working with a product designer, it’s one of the highest-leverage things you can do.
Let's Build Something Smart Together
At Serif Labs, we specialize in early-stage startup design, from 0 to 1 MVP design and rapid prototyping to polished, production-ready design systems. Whether you need a product design consultant or someone to facilitate a sprint and guide your MVP, we’re here to help.
You bring the vision. We’ll help you turn it into something users love.
Ready to design smarter? Let’s talk.
