Go back
Swll - Transforming complex forecast data into a 5-second decision tool for surfers
Year
2026
Design
Quentin Guérandel
Context
The global surfing market is experiencing rapid digitalization, particularly in Europe and the French Atlantic coast. While the demand for accurate forecasting is at an all-time high, the current digital landscape is fragmented. Dominant players provide raw, global data but lack local nuance. Conversely, local apps often suffer from outdated legacy code and poor UX. The market opportunity was clear: a premium, localized tool bridging the gap between raw meteorological data and the immediate decision to surf. I operated as the lead across the entire product lifecycle (0→1), bridging the gap between business strategy, design, and engineering. → Product Strategy: Defined the roadmap, conducted user research (Typeform, Focus Groups), and validated the core value proposition. → UX/UI Design: Built a comprehensive Design System and high-fidelity prototypes. → Technical Bridge: Orchestrated a seamless design-to-dev handoff. I delivered exhaustive technical specifications (edge cases, logic flows) and conducted rigorous QA to ensure the developed product matches the design intent and performance standards.
Problem
Analysis paralysis & cognitive overload
Through user interviews and Typeform surveys, we identified a critical friction point: Cognitive load. Surfers currently juggle between 3 to 5 different apps (wind, swell, tide, webcams) to make a single decision. This results in "analysis paralysis."
→ Data Toxicity: Existing interfaces display dense, raw tables (Excel-like views) that require significant mental effort to decode.
→ The "5-Second" Gap: Users cannot answer "Should I go?" in under 5 seconds.
→ Lack of Personalization: Generic alerts fail to account for a user’s specific level, preferred spots, or local knowledge.
Solution
Radical clarity & "glanceable" intelligence
The idea behind Swll is not just a weather app → it is a decision-making tool. We shifted the paradigm from "displaying data" to "synthesizing insights."
→ UX/UI Design: We designed a card-based interface that aggregates swell height, period, wind direction, and tide into a single, digestible view. The UI hierarchy prioritizes the "Go/No-Go" decision.
→ Atomic Design System: Built a robust, scalable design system. This ensures consistency across iOS and Android while speeding up the dev handoff. Components are modular (Forecast Cards, Spot Headers, Data Rows) allowing for rapid iteration.
→ Localization: Unlike global competitors, Swll focuses on the specificities of French/European spots for now (accurate tide coefficients and culturally relevant spot descriptions).
→ Streamlined Onboarding: A personalized setup flow (validated via wireframes) captures the user's favorite spots, ensuring value delivery on the very first app launch.
Outcomes
Validation & scalable architecture
The project is currently in the development phase, with a modern tech stack (SwiftUI for iOS, Jetpack Compose for Android) to ensure performance and native feel.
→ User Validation:
Focus Group: Achieved a projected NPS of >70 during prototype testing.
Usability: reduced the "time-to-decision" from an average of 2 minutes (from competitor benchmark) to <10 to 15 seconds on Swll.
→ Engineering Standards:
Implementation of a clean architecture pattern to separate business logic from UI code, ensuring the app is scalable.
