UX Engineer, HCI

📍 Job Overview

Job Title: UX Engineer, HCI

Company: Bjak

Location: Seoul, South Korea

Job Type: FULL_TIME

Category: Product Design & Engineering / AI Interfaces

Date Posted: 2026-08-02

Experience Level: Mid-Level (2-5 years)

Remote Status: Hybrid (with potential for remote work within South Korea)

🚀 Role Summary

• Spearhead the development of novel AI-native product interfaces, bridging the gap between cutting-edge Human-Computer Interaction (HCI) principles and practical user experiences.

• Rapidly prototype, test, and iterate on new interaction models for AI-driven applications, focusing on clarity, control, and user trust in ambiguous environments.

• Collaborate closely with cross-functional teams, including Product, Design, and Machine Learning, to translate complex AI behaviors into intuitive and usable interfaces.

• Contribute to the frontend architecture and reusable component library, ensuring scalability and maintainability of AI product surfaces across web and mobile platforms.

📝 Enhancement Note: The role is specifically focused on the "intersection of design and engineering" for "AI-native product interfaces," emphasizing HCI. This suggests a strong need for candidates who can not only build but also conceptualize and validate new interaction patterns for AI, rather than just implementing existing designs. The "AI Interfaces" category is most fitting due to the explicit mention of AI-driven experiences and AI behavior.

📈 Primary Responsibilities

• Architect, build, and prototype advanced AI-native product interfaces for both web and mobile applications, ensuring a seamless user experience.

• Develop functional prototypes for new HCI interaction models, including real-time streaming responses, complex multi-step task flows, dynamic feedback loops, and clear visibility of system states.

• Translate high-fidelity design concepts into robust, production-ready code, prioritizing usability, responsiveness, and sophisticated motion design.

• Experiment with and implement UI patterns designed to clearly communicate AI progress, uncertainty, confidence levels, failures, and recovery mechanisms to users.

• Design and build interfaces that empower users to effectively supervise, correct, and redirect AI operations without requiring granular system micromanagement.

• Engage in close collaboration with product managers, UX/UI designers, and machine learning engineers to rapidly validate and refine interaction concepts.

• Contribute significantly to the overall frontend architecture and the development of a reusable UI component library specifically for AI product surfaces.

• Proactively identify and resolve usability bottlenecks, performance issues, and intricate state management challenges inherent in AI-driven interfaces.

📝 Enhancement Note: The responsibilities highlight a deep dive into the unique challenges of designing for AI, such as managing uncertainty, providing control, and ensuring transparency. The emphasis on "prototyping," "experimenting," and "translating design concepts into working code" points to a hands-on role requiring both conceptual and execution skills. The mention of "frontend architecture" and "reusable UI components" indicates a need for a strong engineering foundation beyond pure prototyping.

🎓 Skills & Qualifications

Education: While no specific degree is mandated, a Bachelor's or Master's degree in Computer Science, Human-Computer Interaction (HCI), Design, or a related field is highly beneficial, demonstrating a foundational understanding of relevant principles.

Experience: 2-5 years of professional experience in frontend engineering, with a significant focus on building interaction-heavy, experimental, or AI-driven user interfaces.

Required Skills:

• Frontend Engineering Mastery: Proficient in modern JavaScript frameworks, with a strong emphasis on React and TypeScript, or equivalent modern frontend technologies.

• HCI & Interaction Design: Deep understanding of Human-Computer Interaction principles and the ability to design for complex AI behaviors, trust, control, and transparency.

• Rapid Prototyping: Demonstrated ability to quickly build functional prototypes in ambiguous environments with incomplete specifications, using tools and techniques that facilitate rapid iteration.

• Product & UX Acumen: Strong product sense and intuitive understanding of user experience, with the capability to identify and articulate usability issues from a user's perspective.

• UI Development: Experience in translating design concepts into high-quality, responsive, and performant code with meticulous attention to detail in usability and motion.

• System Understanding: Familiarity with animation principles, frontend architecture patterns, and UI performance optimization techniques.

• Collaboration: Comfort working at the intersection of design and engineering, fostering effective communication and execution without strict handoff protocols.

• Agility: Ability to maintain a fast pace of development while ensuring the clarity and usability of the user experience.

Preferred Skills:

• Experience with AI/ML integration into frontend applications.

• Familiarity with state management libraries (e.g., Redux, Zustand, Context API).

• Knowledge of mobile development frameworks (e.g., React Native).

• Experience with animation libraries (e.g., Framer Motion, GSAP).

• Understanding of backend integration patterns for AI services.

• Experience with A/B testing and user research methodologies.

📝 Enhancement Note: The "2-5 years" experience level for "Mid-Level" is inferred from the "2-5" range provided in the AI data, which aligns with the responsibilities involving architectural contributions and independent execution, not entry-level tasks. The "AI Interfaces" and "Machine Learning Collaboration" are key skills directly derived from the job description's focus on AI-driven experiences and close work with ML teams.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Demonstrated HCI Innovation: Showcase projects that illustrate novel interaction patterns for AI, focusing on how users interact with and control AI systems.

• Prototyping Prowess: Include examples of rapid prototypes, clearly indicating the tools and methodologies used, and demonstrating the ability to iterate quickly based on feedback or testing.

• Code Quality & Responsiveness: Provide links to live projects or repositories that highlight strong frontend engineering skills, responsive design implementation, and attention to UI performance and animation.

• Problem-Solving Showcase: Present case studies detailing challenges faced in designing for AI interfaces and how these were overcome, emphasizing clarity, control, and user trust.

Process Documentation:

• Workflow Design & Optimization: Document the process of designing and iterating on complex, multi-step task flows for AI applications, showing how user needs were incorporated.

• System State Visualization: Illustrate how you've designed interfaces to clearly communicate the status, progress, and potential issues of AI systems to users.

• Collaboration & Iteration: Detail your approach to working with design and ML teams, emphasizing how feedback was integrated into the development process for AI interfaces.

📝 Enhancement Note: The requirement for a portfolio is explicitly stated for "design roles," and this UX Engineer position sits at the "intersection of design and engineering." Therefore, a strong portfolio demonstrating both engineering capability and UX/HCI thinking is crucial. The emphasis on AI interfaces and interaction models means the portfolio should highlight projects that tackle these specific challenges.

💵 Compensation & Benefits

Salary Range: While not explicitly provided, for a Mid-Level UX Engineer (2-5 years experience) in Seoul, South Korea, with expertise in React, TypeScript, and HCI for AI interfaces, a competitive salary range would typically fall between ₩60,000,000 to ₩100,000,000 per year. This estimate is based on industry benchmarks for similar roles in major tech hubs in South Korea, considering the specialized nature of AI interface development.

Benefits:

• Comprehensive Health Insurance: Coverage for medical, dental, and vision care.

• Stock Options/Equity: Potential for participation in company growth through equity grants.

• Professional Development: Budget for conferences, training, and continuous learning relevant to HCI and AI technologies.

• Flexible Work Arrangements: Hybrid work model allowing for a balance between in-office collaboration and remote flexibility.

• Performance Bonuses: Opportunities for bonuses based on individual and company performance.

• Generous Paid Time Off: Ample vacation days, sick leave, and public holidays.

Working Hours: A standard full-time work week of approximately 40 hours, with flexibility offered through the hybrid work model. The company emphasizes rapid iteration and shipping high-quality work, suggesting a results-oriented environment.

📝 Enhancement Note: Salary estimation is based on general market rates for mid-level software engineering roles in Seoul, South Korea, adjusted upwards due to the specialized nature of AI/HCI expertise and the startup environment which often offers competitive compensation and equity. The benefits are standard for tech companies in major metropolitan areas, with an emphasis on professional development crucial for this role.

🎯 Team & Company Context

🏢 Company Culture

Industry: Technology / Artificial Intelligence / Software Development. Bjak is focused on building AI-native applications that aim to significantly reduce task completion time for everyday users. This positions them at the forefront of applying AI to practical, daily workflows.

Company Size: Small, high-talent density team. The description emphasizes "small, world class teams" and "high talent density," indicating an environment where individual contributions are highly visible and impactful. This likely means a lean, agile structure with direct access to leadership.

Founded: The founding date is not specified, but the company's mission to create a "proactive smart assistant for everyday users" suggests a relatively new or growth-stage company focused on innovation in the AI space.

Team Structure:

• Cross-functional Integration: The team operates with close collaboration between Product, Design, and ML/Engineering. Handoffs are minimized, and individuals are expected to contribute across disciplines.

• High Autonomy & Ownership: Expect a structure that empowers individuals to "exercise judgment, and execute independently." Decision-making is collective, but execution is driven by individual ownership.

• Agile & Iterative: The company culture prioritizes "shipping high quality work and learning" at "rapid speed," indicating a strong emphasis on agile methodologies and continuous improvement.

Methodology:

• Data-Driven Decision Making: While not explicitly stated for this role, the focus on user experience and AI performance implies that data and user feedback are critical inputs for product development.

• Iterative Design & Development: The emphasis on rapid prototyping, testing, and shipping suggests an iterative approach to building and refining features, especially for novel AI interfaces.

• User-Centricity: The mission to "bring intelligence to conversations, errands, organising and workflows" and reduce user time highlights a core focus on solving real user problems and enhancing daily productivity.

Company Website: https://bjak.my/en/about-us

📝 Enhancement Note: The company description points to a startup or growth-stage environment with a strong emphasis on innovation, talent density, and rapid execution. The "small, world class teams" and "high talent density" suggest a competitive but rewarding environment for high-performers. The focus on AI applications for everyday users places Bjak in a rapidly evolving and exciting sector of the tech industry.

📈 Career & Growth Analysis

Operations Career Level: This role is positioned as a Mid-Level UX Engineer, requiring 2-5 years of experience. It's a hands-on engineering role with significant design and HCI responsibilities, sitting at the critical juncture of product development for AI. The role is not about managing people but about driving technical and design innovation for user-facing AI products.

Reporting Structure: While not explicitly detailed, in a small, high-talent density team, reporting lines are typically flat. The UX Engineer will likely report to a Head of Engineering, Head of Product, or a Lead Designer, with direct interaction and collaboration with product managers, designers, and ML engineers.

Operations Impact: The UX Engineer will have a direct and significant impact on the usability, adoption, and effectiveness of Bjak's AI-native products. By crafting intuitive and controllable interfaces for AI, they will directly influence user satisfaction, task completion rates, and the overall success of the company's mission to make AI practical and accessible to billions. Their work is crucial in translating complex AI capabilities into tangible user value.

Growth Opportunities:

• Specialization in AI Interfaces: Deepen expertise in Human-Computer Interaction specifically for AI, becoming a leading voice in designing for AI transparency, trust, and control.

• Technical Leadership: Progress to Senior or Lead UX Engineer roles, taking on more complex architectural challenges, mentoring junior engineers, and influencing frontend strategy.

• Product Strategy Contribution: Contribute more broadly to product strategy and roadmap discussions, leveraging deep understanding of AI capabilities and user interaction patterns.

• Cross-Disciplinary Skill Development: Further hone skills in product management and ML collaboration, potentially transitioning into roles with broader product ownership.

📝 Enhancement Note: The growth analysis focuses on the specialized nature of AI interfaces and the typical career progression for engineers in innovative tech environments. The emphasis is on deepening expertise within the niche, taking on more technical leadership, and potentially expanding into broader product strategy roles, reflecting the dynamic nature of AI development.

🌐 Work Environment

Office Type: The job is listed as "TELECOMMUTE" with a primary location in Seoul, South Korea. The description mentions "virtual meetings and/or onsite," indicating a hybrid work model. The office environment is likely collaborative and modern, designed to foster innovation and teamwork.

Office Location(s): Seoul, South Korea. Specific office details are not provided, but as a tech hub, it's expected to be in a well-connected area conducive to a dynamic work environment.

Workspace Context:

• Collaborative Spaces: Expect an environment that encourages direct interaction with product, design, and ML teams, facilitating rapid idea exchange and problem-solving.

• Technology-Forward: Access to modern development tools, hardware, and software necessary for cutting-edge AI interface development.

• Innovation Hub: A workspace designed to support experimentation, rapid prototyping, and the development of novel interaction paradigms for AI.

• Agile Setup: Likely open-plan or flexible office setups that support quick team huddles and iterative development cycles.

Work Schedule: A standard full-time schedule of approximately 40 hours per week is expected, with the flexibility of a hybrid model. The company's emphasis on rapid shipping and high-quality output suggests a results-oriented culture where focus and efficiency are paramount.

📝 Enhancement Note: Given the "TELECOMMUTE" listing and mention of "virtual meetings and/or onsite," the "Hybrid" work arrangement is the most appropriate inference. This suggests a degree of flexibility, allowing for remote work within South Korea while requiring some presence in or interaction with an office environment in Seoul.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Application & Portfolio Review: Candidates are expected to submit a portfolio. Applications will be evaluated by team members.

• Round 1: Virtual/Onsite Interview: Likely a technical screening focused on frontend engineering skills, HCI principles, and product sense. This may involve discussing past projects and problem-solving approaches.

• Round 2: Design Assessment & Technical Deep Dive: A more in-depth session potentially including a take-home assignment or live coding/design challenge. This will assess rapid prototyping abilities, code quality, and the ability to translate complex AI concepts into user interfaces.

• Final Round: Team & Culture Fit: Discussions with key team members to assess collaboration style, cultural alignment with a fast-paced, high-talent density environment, and overall fit within the company's mission.

Portfolio Review Tips:

• Showcase AI Interaction Design: Prioritize projects that demonstrate your ability to design for AI, focusing on aspects like transparency, control, and managing uncertainty. Clearly articulate the problem, your approach, and the outcome.

• Highlight Rapid Prototyping Skills: Include examples of quick iterations, explaining your process and tools used. Demonstrate your ability to move fast in ambiguous situations.

• Emphasize Code Quality & UX: Provide links to live applications or well-documented code repositories. For UI elements, focus on responsiveness, animation, and how they enhance the user experience.

• Tell a Story: For each project, explain the "why" behind your design and engineering decisions. How did you ensure the interface was understandable, controllable, and useful for the AI's function?

Challenge Preparation:

• HCI & AI Concepts: Brush up on core HCI principles, especially those relevant to AI (e.g., explainability, automation bias, user control).

• Prototyping Tools & Techniques: Be prepared to demonstrate proficiency in rapid prototyping tools and techniques, potentially using React/TypeScript.

• Problem-Solving Scenarios: Anticipate questions about how you would approach designing interfaces for specific AI tasks or challenges, focusing on user understanding and control.

• Communication: Practice articulating complex technical and design concepts clearly and concisely, as you'll be working closely with diverse teams.

📝 Enhancement Note: The job description explicitly mentions a portfolio requirement for design roles and a "design assessment" as part of the interview process. This section provides tailored advice on how to prepare that portfolio and succeed in the assessment, focusing on the unique demands of designing for AI interfaces.

🛠 Tools & Technology Stack

Primary Tools:

• Frontend Frameworks: React (primary), TypeScript.

• Prototyping Tools: Figma, Sketch, Adobe XD (for design handoffs and conceptualization); potentially tools like Framer, ProtoPie, or custom code-based prototypes for functional interactions.

• Version Control: Git, GitHub/GitLab/Bitbucket.

Analytics & Reporting:

• Web Analytics: Google Analytics, Amplitude, Mixpanel (for understanding user behavior on web interfaces).

• Performance Monitoring: Tools like Lighthouse, WebPageTest, or integrated APM solutions for tracking UI performance.

• User Feedback Tools: Hotjar, UserTesting.com, or in-app feedback mechanisms.

CRM & Automation: (Less directly relevant to this role, but foundational for understanding user data)

• While not a direct requirement, familiarity with how CRM data (e.g., Salesforce, HubSpot) might inform user segmentation or how automation tools (e.g., Zapier, Make) could integrate with AI workflows could be beneficial context.

📝 Enhancement Note: The required skills explicitly mention React and TypeScript. The role's focus on prototyping and building interfaces for AI implies the need for robust frontend development tools, version control, and potentially analytics/performance monitoring to ensure the quality and effectiveness of the AI interfaces being built.

👥 Team Culture & Values

Operations Values:

• User-Centricity & Impact: A strong focus on delivering tangible value to users by reducing task completion time and making AI accessible and useful.

• Excellence & High Talent Density: A commitment to hiring and working with top talent, fostering an environment of continuous learning and high-quality output.

• Rapid Iteration & Agility: Valuing speed, efficiency, and the ability to adapt quickly to new information and market changes.

• Collaboration & Collective Decision-Making: A belief in teamwork and shared ownership, where ideas are collectively refined and executed.

• Innovation & Ambition: A drive to build "truly magical products" and bring AI to billions, pushing the boundaries of current technology.

Collaboration Style:

• Integrated Teams: Close-knit, cross-functional teams (Product, Design, ML, Engineering) working with minimal formal handoffs.

• Hands-On & Direct: Individuals are expected to be proactive, contribute directly to problem-solving, and engage in discussions across disciplines.

• Feedback-Oriented: A culture that encourages open feedback for continuous improvement of both products and processes.

• Speed & Execution Focused: While collaborative, the emphasis is on moving fast, making decisions collectively, and executing efficiently to achieve product goals.

📝 Enhancement Note: The company's description of "how we work" provides direct insights into its values and collaboration style. The emphasis on "high talent density," "small, world class teams," "rapid speed," and "collective decisions" clearly shapes the expected culture and interaction patterns within the team.

⚡ Challenges & Growth Opportunities

Challenges:

• Designing for the Unknown: Creating interfaces for AI where established conventions don't yet exist requires significant experimentation and user empathy.

• Balancing AI Complexity and User Simplicity: Making powerful AI capabilities understandable and controllable without overwhelming the user.

• Ensuring Trust and Transparency: Building user confidence in AI systems, especially when they are non-deterministic or prone to errors.

• Rapid Iteration Under Ambiguity: Working effectively in a fast-paced environment with evolving AI models and incomplete specifications.

Learning & Development Opportunities:

• Specialized HCI Expertise: Gaining deep experience in the cutting-edge field of AI interface design, a rapidly growing and highly sought-after skill set.

• Cross-Functional Skill Broadening: Working closely with ML engineers and product managers to gain insights into AI model development and product strategy.

• Architectural Influence: Opportunity to shape the frontend architecture for new AI products and contribute to reusable component libraries.

• Industry Exposure: Engaging with the forefront of AI application development and potentially attending relevant industry events or conferences.

📝 Enhancement Note: The challenges are derived from the core responsibilities and the nature of working with AI interfaces. Growth opportunities focus on the unique specialization this role offers and the typical career advancements within innovative tech companies.

💡 Interview Preparation

Strategy Questions:

• AI Interface Design Philosophy: "How would you approach designing an interface for an AI that needs to handle multi-step tasks with potential failures? What HCI principles would be most critical?" (Focus on transparency, error handling, user control, and feedback loops.)

• Prototyping & Iteration: "Describe a time you had to rapidly prototype a complex interaction with incomplete specifications. What was your process, and how did you validate your ideas?" (Highlight your ability to move fast and iterate effectively.)

• Collaboration Scenarios: "Imagine you disagree with a design decision from the Product team regarding AI transparency. How would you approach this discussion to ensure the best user outcome?" (Emphasize communication, data-driven reasoning, and collaborative problem-solving.)

Company & Culture Questions:

• AI's Role in Daily Life: "What are your thoughts on the future of AI in everyday applications, and what role do you see interfaces playing in its adoption?" (Show your passion and understanding of the company's mission.)

• Working in a High-Talent Environment: "This is a high-talent density team that moves at rapid speed. How do you thrive in such environments, and what are your expectations regarding autonomy and collaboration?" (Align your response with the company's stated culture.)

• Measuring Success: "How would you measure the success of an AI interface you've designed, beyond standard UI metrics?" (Think about task completion rates, user trust, perceived control, and efficiency gains.)

Portfolio Presentation Strategy:

• Structure Your Narrative: For each project, clearly articulate the problem statement, your specific role, the design/engineering process, key decisions made (especially regarding AI interaction), and the measurable impact or learnings.

• Show, Don't Just Tell: Use live demos, interactive prototypes, or well-annotated screenshots/videos. For code-heavy projects, be prepared to walk through key architectural decisions or complex component implementations.

• Focus on HCI for AI: Explicitly call out how your design decisions address the unique challenges of AI interfaces – clarity of AI behavior, user control, trust, and error management.

• Quantify Impact: Whenever possible, use data or metrics to demonstrate the success of your work. If direct metrics aren't available, discuss user feedback or key learnings that drove subsequent iterations.

📝 Enhancement Note: The interview preparation focuses on anticipating questions related to HCI for AI, rapid prototyping, and collaboration within a fast-paced, innovative environment, directly drawing from the job description's requirements and company culture.

📌 Application Steps

To apply for this UX Engineer, HCI position:

• Submit your application through the provided Ashby link, ensuring all required fields are completed accurately.

• Customize Your Resume: Tailor your resume to highlight your experience with React, TypeScript, frontend architecture, rapid prototyping, and any relevant HCI or AI interface projects. Use keywords from the job description.

• Curate Your Portfolio: Select 2-3 of your strongest projects that best showcase your skills in building interactive interfaces, especially those involving complex logic, experimental patterns, or AI. Ensure your portfolio clearly articulates your process and impact.

• Prepare Your Presentation: Practice walking through your portfolio projects, focusing on how you address user challenges, your engineering approach, and your understanding of HCI principles for AI. Be ready to discuss your design and development rationale.

• Research Bjak: Understand the company's mission, products, and the specific challenges of building AI-native applications for everyday users. This will help you tailor your answers and demonstrate genuine interest.

⚠️ 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.

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