05 — about
KarlosZarzu
Senior Product Designer
9+ years working across complex digital products — from marketplaces and e-commerce to global retail platforms. I specialise in UX research and A/B experimentation, always connecting user needs with measurable business outcomes. Based in Barcelona, open to remote.
06 — experience
where I’ve worked
Adevinta · Fotocasa Group
Senior Product Designer
Jan 2022 — Mar 2026
- End-to-end design leadership in high-traffic squads (Fotocasa and Habitaclia), executing an A/B testing roadmap that optimised lead generation and significantly improved the reliability of the registration flow.
- Reduction of technical uncertainty through Continuous Discovery frameworks, transforming qualitative and quantitative insights into high-value product opportunities for Web and App ecosystems.
- Evolution and active contribution to global design systems (SUI and Panot) through the implementation of tokens, optimising handoff efficiency and ensuring visual consistency in a multi-brand architecture.
- Strategic collaboration with C-Level profiles, Product Managers, and Tech Leads, facilitating workshops that unified the long-term product vision and ensured compliance with accessibility standards.
Flat 101
Senior UX/UI Designer & CRO Specialist
Nov 2020 — Jan 2022
- Management of audits and execution of data-driven A/B tests for the Retail and Insurance sectors, achieving a 20% increase in conversion rates for key accounts.
- Creation of Design Systems that reduced development time, standardising documentation and UI Kits to optimise the handoff process.
- Product lifecycle leadership for multiple simultaneous accounts, resulting in a 12% increase in service contracting (upsell) due to the demonstration of measurable results and ROI.
Desigual (via Flat 101)
Senior UX Designer & Researcher
Mar 2020 — Oct 2020
- UX/UI design management for global events (Black Friday and Mid-Season), ensuring frictionless checkout flows and total alignment with brand guidelines.
- Improvement of mobile engagement through user and stakeholder research, transforming qualitative insights into product iterations.
- Development of high-fidelity prototypes for complex digital products to ensure success in the launch of new functionalities.
Interactius
UX Designer & Researcher
Jan 2019 — Mar 2020
- Comprehensive management of Research phases and definition of complex information architectures, achieving greater precision in navigation redesign for critical sectors such as banking and security.
- Management of the full product cycle and direct communication with clients, facilitating Design Thinking and Google Design Sprint workshops to align stakeholders with the project vision.
- Implementation of workflows based on prototyping and constant validation, ensuring the delivery of scalable MVPs for sectors such as Banking, Surveillance, Startups, Sports, E-commerce.
Bershka · Inditex
UX & UI Product Designer
Jul 2018 — Jan 2019
- Creation of the Design System based on Atomic Design for the new global platforms (Web, iOS, Android).
- Design and iteration of personalised UI modules through A/B tests within the Personalization team, using metric analysis to increase user retention.
- Facilitation of Design Sprint and Design Thinking workshops for the ideation of new functionalities.