Prototyping Phase

Building interactive models of a design to test ideas before full development.

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Process

The Prototyping Phase creates tangible representations of design solutions for testing and feedback. Prototypes range from low-fidelity (paper sketches, wireframes) to high-fidelity (interactive Figma prototypes, coded prototypes). The key principle: prototype fidelity should match the question you're trying to answer. Testing navigation? Clickable wireframes suffice. Testing visual design response? You need high-fidelity. Prototypes are disposable — they're tools for learning, not deliverables. The faster you prototype, the faster you learn.

Why It Matters

The prototyping phase is where design concepts are transformed into tangible, testable artifacts that bridge the gap between abstract ideas and functional products. Prototypes expose usability issues, validate assumptions with real users, and create a shared reference point that aligns designers, developers, and stakeholders before expensive engineering work begins. Skipping or rushing prototyping leads to costly rework, misaligned expectations, and products that solve the wrong problems.

Real-World Examples

Paper prototype for navigation testing

A team sketches screens on index cards and asks users to tap on paper elements to complete tasks, testing the information architecture before investing in any digital tools. The lo-fi format encourages participants to give honest feedback because the design clearly looks unfinished and open to change. Three rounds of paper testing reveal a critical navigation flaw that would have taken weeks to fix in code.

Interactive Figma prototype for stakeholder alignment

A design team creates a clickable Figma prototype of a checkout flow and walks stakeholders through it in a meeting, using realistic data and transitions. The prototype surfaces misaligned assumptions about the payment process that written requirements failed to capture. Stakeholders approve the direction with specific, actionable feedback instead of abstract concerns.

Counter-example

Skipping prototyping and building directly

A startup's engineering team begins building a complex onboarding flow directly from a requirements document, bypassing any prototyping. Halfway through development, usability testing of the live build reveals that users cannot complete the flow without assistance, requiring a fundamental restructure. The team loses three weeks of engineering effort that a two-day prototyping sprint would have prevented.

Role-Specific Guidance

Common Mistakes

• Teams frequently over-invest in high-fidelity prototypes too early, spending days perfecting visual details when a rough wireframe would have answered the same research question in hours. Another common error is treating the prototype as the specification, leading developers to reverse-engineer implementation details from a design tool instead of collaborating on a proper handoff. Organizations also sometimes skip prototyping for features that seem simple, only to discover during development that edge cases and user expectations make them far more complex than assumed.