UX Expert - Fraud Prevention

📍 Job Overview

Job Title: UX Expert - Fraud Prevention

Company: Mercado Libre

Location: Osasco, SP, Brazil

Job Type: FULL_TIME

Category: UX/UI Design, Security Operations

Date Posted: 2026-07-23T16:06:44

Experience Level: 5-10 years

Remote Status: Hybrid

🚀 Role Summary

• Lead the end-to-end design of innovative and secure user experiences for fraud prevention, encompassing authentication, identity verification, step-up authentication, blocks, and security alerts.

• Elevate the design team's craft by defining and maintaining visual and interaction quality for security flows across Mercado Libre's platform.

• Design intricate microinteractions and transition states, producing high-fidelity prototypes that clearly communicate design intent, including animations and feedback mechanisms.

• Contribute to and evolve UX patterns for fraud prevention within Mercado Libre's design system, Andes, proposing new components and standards as needed.

• Collaborate cross-functionally with Product, Engineering, Data, and Security teams to translate complex fraud prevention rules into accessible and understandable user flows.

📝 Enhancement Note: While the title is "UX Expert," the responsibilities heavily lean into a specialized UX Design role focused on security and fraud prevention within a large e-commerce and financial services ecosystem. The "operations" aspect is derived from the critical nature of fraud prevention in maintaining the operational integrity and security of the platform.

📈 Primary Responsibilities

• Spearhead the design and delivery of end-to-end fraud prevention user experiences, from initial discovery through to implementation.

• Develop and refine user flows for critical security processes such as authentication, identity verification, step-up authentication, account blocks, and security alerts.

• Systematically conduct and participate in craft reviews with peers to ensure consistent and high-quality visual and interaction design for all security-related user journeys.

• Create detailed, high-fidelity prototypes, incorporating animations and microinteractions, to effectively communicate complex design concepts and user feedback mechanisms to engineering teams.

• Actively contribute to the Andes design system by proposing and developing new components and patterns specifically tailored for fraud prevention scenarios.

• Partner with Product Managers, Engineers, Data Scientists, and Security Specialists to translate complex business logic and fraud rules into clear, intuitive, and human-centered user interfaces.

• Ensure consistency and quality of security experiences by collaborating with design, product, and engineering teams across different verticals within Mercado Pago and Mercado Livre.

• Represent the design perspective in strategic discussions with senior leadership from Product, Security, and Business departments, articulating the user experience impact of proposed strategies.

📝 Enhancement Note: The responsibilities highlight a senior-level UX role with significant strategic influence and direct impact on the operational security and user trust of Mercado Libre's platform. The focus on end-to-end design and cross-functional collaboration is key for operations professionals to understand.

🎓 Skills & Qualifications

Education: While no specific degree is mandated, a strong academic foundation in Human-Computer Interaction, Design, Psychology, Computer Science, or a related field is typically expected for a UX Expert role.

Experience: 5-10 years of progressive experience in UX/UI design, with a significant portion focused on complex digital products, preferably within e-commerce, fintech, or security-related domains.

Required Skills:

• Proven portfolio demonstrating exceptional UI design skills, including precise layouts, consistent visual hierarchy, and mastery of typography, spacing, and color.

• Deep understanding of interaction design principles, with experience in designing sequences of states, microinteractions, and animations that intuitively communicate feedback, progress, and error states.

• Fluent proficiency in Figma, including advanced features like variables, auto layout, conditional logic in prototyping, and well-structured component libraries.

• Demonstrated ability to design user flows that incorporate intentional friction, balancing the urgency of security alerts and blocks with clarity and user comprehension, avoiding unnecessary panic or underestimation of risks.

• Experience utilizing Artificial Intelligence (AI) tools as part of the design process for exploration, variant generation, pattern analysis, and prototyping, coupled with critical evaluation of AI-generated outputs.

• Capacity to navigate and design for complex systems with interdependent flows, non-linear business rules, and exception states that have subtle yet significant user experience impacts.

• Strong ability to defend design decisions with clear, logical reasoning to diverse audiences, including product, engineering, and business stakeholders. Preferred Skills:

• Experience in designing for fraud prevention, security, or identity verification systems.

• Familiarity with Mercado Libre's Andes design system or similar large-scale design systems.

• Understanding of data analysis and its application in informing UX design decisions.

• Experience in user research methodologies and translating research findings into actionable design improvements.

• Knowledge of accessibility standards and best practices.

📝 Enhancement Note: The required skills emphasize advanced UX craft and the ability to manage complexity and intentional friction, which are critical in operations-focused roles like fraud prevention. The explicit mention of AI tools points to a forward-thinking approach in design operations.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Showcase detailed case studies illustrating the end-to-end design process for complex user flows, particularly those involving security or risk mitigation.

• Evidence of strong UI design skills through meticulously crafted layouts, consistent visual hierarchy, and thoughtful use of color and typography.

• Examples of interaction design expertise, including sophisticated microinteractions and animations that enhance user understanding and feedback.

• Prototypes demonstrating advanced Figma skills, such as conditional logic, component states, and dynamic layouts.

• Case studies that highlight how AI tools were integrated into the design process and the impact they had on efficiency or design outcomes.

• Demonstrations of how complex business rules and system constraints were translated into clear and accessible user experiences. Process Documentation:

• Clearly articulate the design process followed for each case study, detailing phases such as discovery, research, ideation, prototyping, testing, and iteration.

• Document the rationale behind design decisions, supported by user research, business requirements, and technical constraints.

• Illustrate the collaborative process with product, engineering, and security teams, showing how feedback was incorporated and how cross-functional alignment was achieved.

• Showcase the evolution of designs, including iterations based on user testing, A/B testing, or performance data related to fraud detection rates or user friction.

📝 Enhancement Note: For a role like this, the portfolio is paramount. It needs to demonstrate not just aesthetic skills but a rigorous design process applied to operational challenges like fraud. The emphasis on translating complex rules and using AI highlights the need for process documentation that shows strategic thinking.

💵 Compensation & Benefits

Salary Range: For a UX Expert with 5-10 years of experience in a major tech hub like Osasco, Brazil, the estimated salary range could be between R$10,000 to R$18,000 per month, depending on the specific experience, skills, and negotiation. This is based on general market data for senior UX/UI roles in Brazil, considering the industry and company size.

Benefits:

• Comprehensive health and dental insurance plans.

• Life insurance coverage.

• Meal vouchers (Vale Refeição/Alimentação) typical in Brazil.

• Employee assistance programs and well-being initiatives.

• Opportunities for professional development, training, and conference attendance.

• Potential for performance-based bonuses or profit-sharing.

• Access to Mercado Libre's extensive employee discount programs.

• Hybrid work model offering flexibility.

Working Hours: Standard full-time working hours, likely around 40 hours per week, with a hybrid model requiring some days in the Osasco office. Flexibility may be offered within team agreements.

📝 Enhancement Note: Salary estimates are based on current market research for senior UX roles in Brazil, specifically within large technology companies. Benefits are typical for major Brazilian employers, with a focus on well-being and professional growth relevant to operations and design professionals.

🎯 Team & Company Context

🏢 Company Culture

Industry: E-commerce, Financial Services (Fintech), Technology. Mercado Libre is a dominant force in Latin America's digital commerce landscape, offering a wide range of products and services, including payment solutions through Mercado Pago. The fraud prevention aspect is critical to the operational integrity of both these arms.

Company Size: Large enterprise, with tens of thousands of employees globally. This scale implies robust processes, significant impact, and opportunities for specialized roles.

Founded: 1999. With over two decades of operation, Mercado Libre has a mature organizational structure and a deep understanding of its market, fostering an environment of continuous innovation and adaptation in areas like security operations.

Team Structure:

• The UX team likely operates within a larger Product or Technology division, with specialists focusing on different areas like core e-commerce, payments, or specialized security functions.

• Reporting structure would typically involve a UX Lead or Manager, with direct reporting lines from UX Experts.

• Cross-functional collaboration is essential, with UX Designers working closely with Product Managers, Engineers (Frontend, Backend, AI/ML), Data Scientists, Security Analysts, and other stakeholders to deliver integrated solutions. Methodology:

• Data-driven design is a core methodology, leveraging analytics, A/B testing, and user research to inform design decisions and measure impact.

• Agile development methodologies are likely employed, enabling rapid iteration and continuous improvement.

• A strong emphasis on user-centric design principles, ensuring that solutions are not only secure but also intuitive and easy for users to navigate, even in high-stakes situations.

• Application of AI and Machine Learning is integral to fraud detection and prevention strategies, and UX plays a role in designing the interfaces and user interactions around these technologies.

Company Website: https://www.mercadolibre.com/

📝 Enhancement Note: Mercado Libre's culture is characterized by innovation, a focus on solving real-world problems at scale, and a commitment to democratizing commerce and finance in Latin America. For a UX Expert in fraud prevention, this means working on high-impact projects with a strong emphasis on security and user trust within a dynamic, technology-driven environment.

📈 Career & Growth Analysis

Operations Career Level: This "UX Expert" role represents a senior individual contributor position within the UX discipline. It demands a high degree of autonomy, strategic thinking, and the ability to influence product direction. In an operations context, this role is critical for maintaining the security and efficiency of the platform by designing robust fraud prevention mechanisms.

Reporting Structure: The UX Expert will likely report to a UX Manager or Lead, who oversees a team of designers. They will also collaborate extensively with Product Managers, Engineering Leads, and Security Directors, providing a broad exposure to different facets of the business operations.

Operations Impact: The primary impact of this role is on operational stability and risk mitigation. By designing effective fraud prevention measures, the UX Expert directly contributes to reducing financial losses, protecting users, maintaining platform integrity, and ensuring compliance with financial regulations. This role is crucial for the smooth functioning of Mercado Libre's e-commerce and financial services operations.

Growth Opportunities:

• Specialization: Deepen expertise in UX for security, fraud prevention, or specific areas of financial technology.

• Leadership: Transition into a UX Lead or Manager role, managing a team of designers and setting design strategy.

• Cross-functional Mobility: Move into Product Management, focusing on security product strategy, or into a specialized Data Science or AI role related to fraud detection.

• Mentorship: Become a mentor for junior designers, contributing to the development of the broader UX community within Mercado Libre.

• Global Exposure: Participate in projects with international scope within Mercado Libre's diverse markets.

📝 Enhancement Note: The growth trajectory for a UX Expert in this specialized area is strong, moving from individual contribution to leadership or strategic product ownership, all within the critical operational domain of security and fraud.

🌐 Work Environment

Office Type: The role is designated as Hybrid, requiring a presence in the Osasco, SP office. This suggests a modern office space designed to facilitate both focused individual work and collaborative team activities.

Office Location(s): Osasco, São Paulo, Brazil. This location is a significant business hub, offering accessibility and a vibrant professional ecosystem.

Workspace Context:

• The workspace is expected to be equipped with modern technology and tools necessary for high-fidelity design and prototyping.

• Collaborative spaces will be available for team meetings, brainstorming sessions, and cross-functional workshops, crucial for aligning on complex security solutions.

• The environment will foster interaction with diverse teams (Product, Engineering, Data Science, Security), promoting a holistic understanding of the business and its operational challenges.

• Access to company-wide resources, including design systems and research repositories, will support efficient workflow.

Work Schedule: A standard 40-hour work week is typical, with the hybrid model allowing for a balance between remote work and in-office collaboration. Specific in-office days may be determined by team needs and management direction.

📝 Enhancement Note: The hybrid model in a major Brazilian tech hub indicates a professional, collaborative, and well-resourced work environment conducive to complex UX design challenges within an operational context.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: HR or Recruiter call to assess basic qualifications, cultural fit, and interest in the role.

• Portfolio Review & Technical Interview: A deep dive into the candidate's portfolio, focusing on specific case studies. Expect detailed questions about their design process, decision-making rationale, challenges faced, and outcomes achieved, particularly in complex or security-related projects. This stage often involves a design exercise or a presentation of a past project.

• Cross-functional Interviews: Discussions with Product Managers, Engineering Leads, and potentially Security Analysts to evaluate collaboration skills, understanding of technical constraints, and ability to translate business requirements into design solutions.

• Senior Leadership Interview: A final conversation with a Director or VP level stakeholder to assess strategic thinking, leadership potential, and overall fit with Mercado Libre's vision and culture.

Portfolio Review Tips:

• Curate Strategically: Select 2-3 strong case studies that best highlight your expertise in complex UX design, interaction design, UI craft, and ideally, experience with security, fraud, or risk-related challenges.

• Focus on Process: Clearly articulate your end-to-end design process for each case study. Use visuals to show user flows, wireframes, prototypes, and final UI.

• Highlight Problem-Solving: Emphasize the specific problems you were trying to solve, the constraints you worked within (business, technical, security), and how your design decisions addressed these.

• Quantify Impact: Whenever possible, include metrics demonstrating the success of your designs. For fraud prevention, this could be reduced fraud rates, improved user trust, decreased support tickets related to security, or increased adoption of security features.

• Showcase Figma Mastery: Be prepared to discuss your use of Figma features like auto layout, components, variants, and prototyping logic. If AI tools were used, explain how and the impact.

• Tell a Story: Structure your case studies as narratives – problem, approach, solution, and results.

Challenge Preparation:

• Design Exercise: Be prepared for a design challenge, which might involve solving a hypothetical fraud prevention scenario or improving an existing flow. Focus on your thought process, user-centricity, and ability to consider edge cases and security implications.

• Stakeholder Management: Practice articulating your design rationale clearly and concisely, anticipating questions from technical and business stakeholders. Be ready to defend your choices with data and logical reasoning.

• System Thinking: Demonstrate an understanding of how your design fits into the larger ecosystem of Mercado Libre’s platform and operations.

📝 Enhancement Note: The interview process and portfolio review are critical. Candidates must showcase not just design talent but a deep understanding of operational challenges like fraud prevention, strong collaboration skills, and the ability to quantify impact.

🛠 Tools & Technology Stack

Primary Tools:

• Figma: Essential for UI design, prototyping, and collaboration. Mastery of advanced features (variables, auto layout, conditional logic) is expected.

• Prototyping Tools: Beyond Figma's capabilities, familiarity with dedicated prototyping tools might be beneficial for complex animations or interactions.

• Design Systems: Deep understanding and contribution to design systems (like Andes) are crucial for maintaining consistency across the platform.

Analytics & Reporting:

• Data Analysis Tools: While not directly using them, understanding how to interpret data from tools like Amplitude, Google Analytics, or internal dashboards is important for informing design decisions and measuring impact.

• A/B Testing Platforms: Familiarity with how A/B tests are conducted and how results are analyzed to validate design choices.

CRM & Automation:

• Not directly applicable to UX design in the same way as for Ops roles, but understanding how user data impacts the systems they interact with is key.

• Project Management Tools: Familiarity with tools like Jira or Asana for tracking design tasks and collaborating with engineering teams.

• AI/ML Platforms: Understanding how AI/ML models are used in fraud prevention and how to design interfaces that integrate with or explain these systems.

📝 Enhancement Note: The technology stack is heavily focused on design tools, with a strong emphasis on Figma and design systems. Understanding the operational context of AI/ML in fraud prevention and how to design around it is a key differentiator.

👥 Team Culture & Values

Operations Values:

• User-Centricity: Designing experiences that are secure, intuitive, and trustworthy for millions of users across Latin America.

• Innovation: Continuously seeking new ways to improve security and user experience, leveraging cutting-edge technology like AI.

• Collaboration: Working effectively across diverse teams (Product, Engineering, Data, Security) to achieve common goals.

• Impact: Focusing on delivering solutions that have a tangible positive effect on the business, such as reducing fraud and enhancing user safety.

• Accountability: Taking ownership of design decisions and their outcomes, with a commitment to continuous learning and improvement.

Collaboration Style:

• Cross-functional Integration: UX designers are embedded within product teams, working hand-in-hand with Product Managers and Engineers.

• Data-Informed: Design decisions are heavily influenced by data analysis, user research, and performance metrics.

• Iterative Development: A culture of continuous improvement, where designs are tested, refined, and iterated upon based on feedback and performance.

• Open Communication: Encouraging candid feedback and constructive criticism to elevate the quality of design work.

📝 Enhancement Note: The team culture values a blend of user advocacy, technical innovation, and a strong sense of shared responsibility for the platform's operational integrity and success.

⚡ Challenges & Growth Opportunities

Challenges:

• Balancing Security and Usability: Designing fraud prevention flows that are robust enough to deter criminals but not so cumbersome that they alienate legitimate users. This is a core operational challenge.

• Complexity of Fraud: Adapting designs to constantly evolving fraud tactics and sophisticated attack vectors requires continuous learning and agile design responses.

• System Interdependencies: Designing within a vast and interconnected ecosystem where changes in one area can have unforeseen impacts on others requires meticulous planning and collaboration.

• AI Integration: Effectively integrating AI-driven insights or features into user experiences, ensuring transparency and trust without overwhelming users.

Learning & Development Opportunities:

• Specialized Training: Access to workshops and courses on advanced UX techniques, security design principles, and AI in design.

• Industry Conferences: Opportunities to attend leading UX, product, and security conferences.

• Mentorship Programs: Pairing with senior designers or leaders within Mercado Libre for career guidance and skill development.

• Internal Mobility: Potential to explore roles in other product areas or even adjacent operational functions within the company.

📝 Enhancement Note: The challenges directly reflect the operational complexities of securing a large-scale platform. Growth opportunities are geared towards deepening expertise in this critical domain or broadening into related strategic roles.

💡 Interview Preparation

Strategy Questions:

• "Describe a time you had to design a user flow with intentional friction. How did you balance security needs with user experience?" (Focus on your process for understanding risk, user impact, and iterative testing.)

• "How would you approach designing an end-to-end authentication and identity verification flow for a high-risk transaction? What are the key considerations?" (Discuss user journeys, security layers, error handling, and compliance.)

• "Imagine a new type of fraud is detected impacting our platform. How would you collaborate with Product, Engineering, and Data Science to quickly design and implement a mitigation strategy?" (Emphasize rapid prototyping, iterative design, and cross-functional communication.) Company & Culture Questions:

• "Why are you interested in designing for fraud prevention at Mercado Libre, specifically?" (Connect your passion for user protection and operational integrity with Mercado Libre's mission.)

• "How do you stay updated on the latest trends in UX design, security, and fraud prevention?" (Showcase continuous learning and proactive engagement with the field.)

• "Describe your experience working with design systems like Andes. How do you contribute to and leverage them?" (Highlight your understanding of scalable design and component-based architecture.) Portfolio Presentation Strategy:

• Start with the "Why": Clearly articulate the business problem and user need behind each case study.

• Show, Don't Just Tell: Use visuals (screenshots, prototypes, flow diagrams) to illustrate your process and solutions.

• Explain Your Decisions: For every design choice, explain the rationale, referencing user research, business goals, or technical constraints.

• Quantify Results: Present metrics that demonstrate the success of your design solutions, especially in terms of fraud reduction or user experience improvement.

• Discuss Collaboration: Explain how you worked with other teams (Product, Engineering, Data) and how you handled feedback or disagreements.

• Be Ready for Deep Dives: Anticipate detailed questions about specific screens, interactions, and your role in the project.

📝 Enhancement Note: Interview preparation should focus on demonstrating a deep understanding of UX principles applied to operational security challenges, strong collaboration skills, and the ability to articulate a clear, data-informed design process.

📌 Application Steps

To apply for this UX Expert - Fraud Prevention position:

• Submit your application through the provided link on the Mercado Libre careers portal.

• Portfolio Customization: Curate your portfolio to prominently feature 2-3 case studies that best showcase your expertise in complex UX/UI design, interaction design, and any experience related to security, fraud prevention, or risk management. Ensure each case study clearly outlines the problem, your process, your solutions, and the measurable impact.

• Resume Optimization: Tailor your resume to highlight keywords from the job description, such as "UX Design," "Fraud Prevention," "Interaction Design," "Figma," "Design Systems," "AI," and "Security Design." Quantify achievements with specific metrics where possible.

• Interview Preparation: Practice articulating your design process and rationale for key projects. Prepare to discuss how you handle intentional friction, collaborate with technical teams, and leverage AI tools. Be ready to present your portfolio and answer strategic questions about user experience in security contexts.

• Company Research: Familiarize yourself with Mercado Libre's mission, products (especially Mercado Pago), and its role in Latin American e-commerce and financial services. Understand the importance of fraud prevention within their operational framework.

⚠️ Important Notice: This enhanced job description includes AI-generated insights and operations industry-standard assumptions. All details should be verified directly with the hiring organization before making application decisions.