To validate user interaction patterns without premature backend complexity, OpenAI designers build fully interactive UI prototypes directly in the codebase. These connect to a non-functional "painted door" backend, allowing the team to gather real usage data before committing engineering resources to full implementation.

AI-powered "vibe coding" is reversing the design workflow. Instead of starting in Figma, designers now build functional prototypes directly with code-generating tools. Figma has shifted from being the first step (exploration) to the last step (fine-tuning the final 20% of pixel-perfect details).

By enabling teams to share live, clickable prototype URLs, Stripe shifted its design reviews away from static Figma presentations. This "Demos, Not Memos" approach allows stakeholders to interact with the product directly, leading to more tangible and higher-quality feedback.

Instead of designing in Figma first, Ron Goldin used AI to generate a functional but ugly "build wireframe" for his product. This approach allows for rapid iteration on core flows and architecture, ensuring the product feels right before investing in high-fidelity design.

When production code is the only source of truth, designers use AI to capture the live product and convert it back into a high-fidelity, componentized Figma file. This solves the common issue of undocumented engineering changes creating design drift.

Instead of creating static mockups in Figma, Cursor's design team prototypes directly in their AI code editor. This allows them to interact with the "life states of the app" and get a more realistic feel for the product, bridging the gap between design and engineering.

The key advantage of vibe prototyping is rapid iteration. Integrating authentication and live databases too early introduces complexity and technical debt, slowing the process. The best practice is to focus on front-end validation first, using fake data to simulate the backend.

Instead of getting bogged down in production constraints like failing tests, designers are encouraged to use code to render the most desirable version of an idea. The prototype's value is in communicating the full vision to engineering, not in being a mergeable pull request.

High-fidelity, code-based prototypes are replacing static mockups as the primary artifact for design-to-engineering handoffs. At Stripe, engineers can use the prototype's code as a direct source of truth, minimizing translation errors and ambiguity from design to production.