
Guilherme Cerqueira
Verified Expert in Design
Designer
São Paulo - State of São Paulo, Brazil
Toptal member since January 27, 2022
Guilherme is a seasoned UI/UX product designer with over 15 years of experience. He has a proven track record in designing for millions of users at Booking.com and helping numerous SaaS startups achieve success through his user-centered and data-informed design solutions. With extensive experience in web and mobile app design, including UX thinking, research, wireframing, and prototyping, Guilherme has worked with a range of companies with clients such as GSK, Unilever, Danone, Nestlé, and BRF.
Portfolio
Work Experience
Lead Product Designer
WithClutch
- Led the end-to-end ideation, research, design, development, maintenance, and documentation of the company's design system, streamlining cross-product consistency and accelerating design-to-dev handoff.
- Spearheaded multiple design projects from discovery to launch, defining the UX vision and delivering solutions that balanced user needs with business goals across web and mobile platforms.
- Conducted usability studies, stakeholder interviews, and data analysis to inform and iterate on product decisions, ensuring every design was rooted in user insight.
- Facilitated cross-functional design reviews, mentored teammates, and helped raise the overall UI/UX quality by establishing best practices and fostering a human-centered design culture.
- Collaborated closely with the head of product and design to shape the product strategy and embed design thinking into the company's roadmap, improving alignment between product, engineering, and business teams.
Lead Designer
Proxa AI
- Translated complex data hub wireframes into polished, pixel-perfect Figma designs, improving clarity and implementation readiness.
- Designed and refined UI components with a strong focus on usability and visual cohesion, contributing to a more intuitive user experience across the platform.
- Created a streamlined style guide in Figma to ensure design consistency, scalability, and cross-functional alignment throughout the project lifecycle.
- Participated in Agile ceremonies, including biweekly sprints, daily stand-ups, and demos, and provided design recommendations and adapted to evolving project needs.
- Collaborated closely with developers and stakeholders to refine requirements, align on technical feasibility, and incorporate user feedback into iterative design improvements.
Senior Product Designer
Filtered
- Designed and shipped new product features from concept to implementation, enhancing the user experience for candidates taking technical assessments on the hiring platform.
- Maintained and evolved core user journeys by identifying friction points and refining interaction patterns across key flows.
- Collaborated with developers to create high-fidelity wireframes and design specs, accelerating the build process and ensuring design quality.
- Led updates to the design system, ensuring visual and functional consistency across the platform as it scaled to support new enterprise clients.
- Contributed to strategic product direction through regular brainstorming sessions with cross-functional teams, aligning design decisions with user needs and business goals.
Senior Product Designer
Wisdom AI
- Collaborated directly with the CPO to define the product's user experience for the web and mobile app from the ground up, including building the product roadmap and features.
- Created wireframes, low-fidelity mockups, UI elements, and high-fidelity MVP prototypes for the company to prospect clients and build a pitch deck.
- Designed 200+ screens with flows and interactions to understand user behavior and to communicate the content to the client.
- Designed the MVP for the main product and the admin dashboard.
- Produced multiple iterations based on stakeholder and user feedback.
- Set up the design vision with new features and use cases.
- Created fully functional, high-fidelity prototypes for the web and mobile app.
- Worked closely with front-end developers to implement the features.
Lead Product Designer
New Fitness App concept
- Developed comprehensive user flows, ensuring that every single interaction within the fitness app was thoughtfully designed.
- Created detailed wireframes serving as the architectural framework for the app, ensuring a solid foundation for an intuitive and user-friendly interface.
- Designed lo-fi and hi-fi prototypes, allowing for hands-on testing, feedback gathering and refinement.
Senior UI/UX Designer
eSpeakers.com, Inc.
- Designed a new user-friendly booking experience for the platform, focusing on conversion rate optimization.
- Redesigned the whole website and platform from scratch for web and mobile.
- Created high-fidelity prototypes ready for developer handoff, including colors, typography, new components, and assets.
Senior Product Designer
Anima
- Designed a Figma plugin that helps developers and designers to automate front-end code directly from the software. The plugin is ranked first in the development category, with over 350,000 installations.
- Drove discussions, research, and study. Created user stories and personas and mapped user journeys. Made presentations, sketches, drafts, designs, components, and assets.
- Improved the user experience by analyzing qualitative and quantitative data and applying it to prototypes and final releases.
- Redesigned the user interface for the plugin and web app while creating and maintaining components for the design system.
Product Designer
Booking.com
- Ran hundreds of experiments and A/B testing for user experience optimization of web and mobile apps and eCommerce and internal tools. Created all the designs, prototypes, and scenarios for testing and iterations.
- Designed experiences, pages, tools, and A/B tests for global campaigns like Black Friday and New Year. Created, idealized, organized, and rolled out tools for speeding up the release of campaigns.
- Drove discussions, research, and study. Created user stories and personas. Mapped user journeys and made presentations, sketches, drafts, designs, components, and assets.
- Created, designed, and optimized the user experience of internal tools for partners to manage their properties.
Senior UI/UX Designer
Trade Force (now Neogrid)
- Owned the whole design process for the Trade Force web portal and Trade Force field team app, from scratch to release. Some clients who used the product include Unilever, BRF, GSK, Danone, and L'Oréal.
- Realized the competition analysis, user research, user flows and stories, personas definition, wireframes, low-fidelity and high-fidelity prototyping, usability testing, experimentation, and iterations for web and mobile apps.
- Created, idealized, and designed administrative dashboards and systems for retail management.
- Shadowed field users to understand their pain points and iterate on improvements in the mobile app.
- Utilized design thinking and Lean Design methodologies to constantly iterate and improve the products.
UI/UX Designer
Neolog
- Designed a web app for the whole logistics management process, from collection to delivery, reducing travel time and costs.
- Performed heuristic analysis for the old EXE application, drew user flows, created hypotheses, and discussed with stakeholders to validate wireframes.
- Created and coded HTML and CSS for more than 50 screens.
UI/UX Designer
Intuitive Intelligence CRO
- Created hundreds of A/B tests for some of the biggest eCommerce companies from Brazil, such as Fnac, Nova.com, Ponto Frio, and Americanas.
- Designed a web app and dashboard that monitors the eCommerce competition prices and compares the client's product prices in real time.
- Created a mobile app that monitors product inventory at points of sale.
UI/UX Designer
Freelance
- Managed and oversaw the UX thinking, wireframing, prototyping, and UI design execution.
- Created a system that made it easy for clients to upload photos, add information, and sell and rent their holiday property in the Spanish market.
- Designed and coded several websites for small companies.
- Constructed WordPress themes for clients to update the content on websites easily.
Web Designer
Doors Agency
- Designed landing pages for Brazilian celebrities in accordance with their sponsors and marketing activities.
- Created hot campaign sites for promotions and marketing purposes for big Brazilian brands.
- Built and coded email marketing campaigns and created templates.
Landing Page Designer and Online Campaign Manager
SEO Marketing
- Created, implemented, maintained, and iterated Google AdWords campaigns for small, mid-sized, and big clients.
- Designed and built landing pages for conversion optimization.
- Used heat maps, surveys, hypothesis validation, and data analysis to create iterations for landing pages.
Education
Master's Degree in Web Applications
Universidad Politecnica de Valencia - Valencia, Spain
Bachelor's Degree in Advertising and Marketing
Escola Superior de Propaganda e Marketing - Sao Paulo, Brasil
Skills
Tools
Sketch, Photoshop CC, Anima, UX Tools, InVision, Hotjar, Usertesting.com, Adobe Illustrator, Illustrator CC, Figma Plugins, eCommerce Dashboards
Languages
HTML5, HTML, CSS, JavaScript
Platforms
Figma, Mobile, iOS, Google Ads, Adobe Suite, Android
Other
User Experience (UX), UX Design, Web UX Design, App Design, iOS UX Design, UI Design, Web UI Design, A/B Testing, Web UX, Web App UX, iOS UI Design, Wireframing, Prototyping, Lean Product Development, Product Design, Digital Product Design, User Flows, Mobile App Design, Web UI, Web Dashboards, Dashboards, Mobile Apps, App UI, Mobile UI, User Interface (UI), eCommerce UX, User Testing, Mobile UX, User Experience Design, User Experience Strategy, App UX, Web App UI, Startups, Mockups, Rapid Prototyping, Web App Design, Responsive Web Design (RWD), Web Design, Dashboard Design, SaaS Design, SaaS, B2B, Mobile Design, eCommerce, eCommerce Design, eCommerce UI, UI Components, B2C, Responsive UI, User Journeys, User Personas, B2B2C, UX Documentation, Conversion Rate Optimization (CRO), Conversion Rate, UI Libraries, Layout, Enterprise SaaS, Software as a Service (SaaS), Interaction Design (IxD), Mobile UI Design, Mobile UX Design, Data Visualization, Web Applications, Web & Mobile Applications, Enterprise Design, Business Technology, Software Design, Customer Journeys, Interactive Prototypes, Layout Design, Component Libraries, Responsive Web Apps, UX Strategy, UX Wireframes, Responsive Development, Sitemaps, User Journey Maps, Business to Business to Consumer (B2B2C), User Stories, Conversational UI, Conversational UX, Conversational Design, Usability, Data-heavy Design, User Research, Experimental Design, UX Research, Design Systems, Design Thinking, Lean UX, Hypothesis Testing, Personas, Front-end, Visual Design, Style Guides, Landing Page Design, Landing Pages, Geolocation, Branding, Music Production, Storyboarding, Artificial Intelligence as a Service (AIaaS), Advertising Design, B2C Marketing, Web Marketing, User Psychology, Android UI Design, Lean Experiments, Web Analytics, React, Plugins, Mobile First, Mobile eCommerce, Travel, Travel Design, Artificial Intelligence (AI), Design Workshops, Conversion, Design Leadership, Market Research, Graphic Design, Conversational Interfaces, AI Design, Chatbots, ChatGPT, Notion, UX Flows, Fintech, Fintech Design, Fintech Consultant, Mobile Banking, Online Banking, Digital Banking, Design Ops, UX Testing, UI Testing, UI Research, Due Diligence, Portal Design, Web Portals, Business to Business (B2B), Business to Consumer (B2C), User Portal Design, Platform Design, Storybook, Mobile Web, Mobile Web Design, UX Prototyping, UI Prototyping, Workshops, UX Workshops, UX Review, DataViz, Analytics, Data Analytics, Text Analytics, Conversational AI, Admin Panels
Experience
- UI Design - 14 years
- Product Design - 14 years
- UX Design - 14 years
- Prototyping - 12 years
- SaaS Design - 11 years
- Mobile Design - 10 years
- Design Systems - 8 years
- A/B Testing - 8 years
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