I’m a lead product designer with over 7.5 years of experience creating clear, trustworthy experiences for two-sided marketplaces. I’ve led discovery and end-to-end product design for sellers, hosts, travelers, and millions of consumers across Allegro, LocalBini, and STRADE, turning complex problems into simple, shippable solutions that improve conversion, supply growth, and customer satisfaction. I enjoy working closely with research, Product, and Engineering teams to understand people’s needs, test ideas, and bring products from zero-to-one concepts through launch. My background in cognitive science helps me approach challenges with curiosity, while my hands-on experience with design systems, prototyping, and front-end constraints helps me make thoughtful ideas practical and impactful.

Karolina Zmarzły

I’m a lead product designer with over 7.5 years of experience creating clear, trustworthy experiences for two-sided marketplaces. I’ve led discovery and end-to-end product design for sellers, hosts, travelers, and millions of consumers across Allegro, LocalBini, and STRADE, turning complex problems into simple, shippable solutions that improve conversion, supply growth, and customer satisfaction. I enjoy working closely with research, Product, and Engineering teams to understand people’s needs, test ideas, and bring products from zero-to-one concepts through launch. My background in cognitive science helps me approach challenges with curiosity, while my hands-on experience with design systems, prototyping, and front-end constraints helps me make thoughtful ideas practical and impactful.

Available to hire

I’m a lead product designer with over 7.5 years of experience creating clear, trustworthy experiences for two-sided marketplaces. I’ve led discovery and end-to-end product design for sellers, hosts, travelers, and millions of consumers across Allegro, LocalBini, and STRADE, turning complex problems into simple, shippable solutions that improve conversion, supply growth, and customer satisfaction.

I enjoy working closely with research, Product, and Engineering teams to understand people’s needs, test ideas, and bring products from zero-to-one concepts through launch. My background in cognitive science helps me approach challenges with curiosity, while my hands-on experience with design systems, prototyping, and front-end constraints helps me make thoughtful ideas practical and impactful.

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Experience Level

Expert
Expert
Expert
Expert

Language

Polish
Fluent
English
Advanced
German
Intermediate

Work Experience

Senior User Experience Designer at STRADE
August 1, 2024 - July 1, 2026
Owned discovery and end-to-end design for complex seller workflows in a regulated B2B marketplace for aircraft parts. Identified trust barriers preventing suppliers from adding inventory, with research and workshops contributing to more than 1,400 new listings. Partnered with Product and Engineering while building a scalable Figma design system.
Senior Product Designer at LocalBini
June 1, 2024 - Present
Led discovery and product design across both sides of a travel marketplace connecting local hosts with travelers. Improved booking and performance journeys, increasing host satisfaction and reducing support requests by 19%. Translated customer and business needs into tested, shippable solutions.
Senior User Experience Designer at Allegro
April 1, 2023 - July 1, 2024
Led discovery for an international expansion of a large-scale e-commerce marketplace, identifying trust as a barrier to supply and inventory growth. Designed seller decision tools and consumer journeys across payments, subscriptions, purchases, and accounts. Reframed a failed-payment journey, contributing to 12% more recovered payments and approximately PLN 16 million in recovered monthly GMV. Mentored designers and collaborated with Product and Engineering from discovery through launch.
Research Lecturer at AGH University
February 1, 2023 - April 1, 2024
Taught UX research, usability testing, and user-centered design while guiding students through research and design projects.
User Experience Designer at Allegro
August 1, 2020 - March 1, 2023
Designed seller decision tools and consumer journeys across payments, subscriptions, purchases, and accounts for a large-scale e-commerce marketplace. Worked on discovery, product design, and improvements to critical customer and business workflows.
UX/UI Designer at Skytech
January 1, 2019 - July 1, 2020
Designed responsive digital products from wireframes through high-fidelity user interfaces and implementation-ready specifications. Built interfaces in HTML and CSS, developing a practical understanding of front-end constraints.
Research Coordinator at Jagiellonian University
October 1, 2016 - January 1, 2020
Coordinated EEG and behavioural research and trained researchers in experimental methods and procedures.

Education

Postgraduate Degree in UX and Product Design at AGH University
January 1, 2019 - January 1, 2020
Master and Bachelor Degree in Cognitive Science at Jagiellonian University
January 1, 2013 - January 1, 2018

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Travel & Hospitality, Retail, Wholesale & Distribution, Transportation & Logistics, Education