Decide quickly, with evidence. Prototyping-testing illuminates choices without launching a full redesign. We start from a clear question (‘Which proposition delivers the most value?’, ‘Where is the obstacle?’), formulate hypotheses, then create the right level of prototype: paper sketch, wireframes, interactive mockups, or mini front-end prototype. Next, we test with real people — in context — to gather insights that truly guide decisions. Our approach is progressive: short framing, simple protocol, rapid sessions, immediately actionable synthesis. We measure understanding, effort, emotion, and journey success. We also check accessibility fundamentals (contrast, focus, alternatives) from the mockup phase, because catching a problem early costs 10x less later. When a decision remains risky, we escalate: POC, fake door, light A/B test — just enough. Connections with other hubs create a true vortex. Towards Design: insights feed structured UX Design and the Design System (tokens, components, guidelines), or refine branding-identity (tone, hierarchy, typographic greys). Towards Tech: feasibility for custom web development is checked, API contracts prepared, API automation anticipated (webhooks, integrations), sustainable web performance protected (weight, latency), and the CI/CD loop integrated for fast, frequent testing. Towards Consulting: we feed audits, reduce strategic framing uncertainty, establish product governance rituals (regular tests, decision log), and disseminate practices via training-sensitisation. Deliverables: test protocol, Figma/mini-prototypes, short reports (verbatims, problems, opportunities), priorities and recommendations, Design System updates, experience backlog.