Product Designer (UX), HCI

📍 Job Overview

Job Title: Product Designer (UX), HCI

Company: Bjak

Location: London, England, United Kingdom

Job Type: Full-time

Category: Product Design / UX / HCI

Date Posted: May 21, 2026

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

Remote Status: Hybrid (Remote within the UK)

🚀 Role Summary

• Design innovative user experiences for a proactive AI smart assistant, focusing on human-AI interaction (HCI) and trust-building.

• Develop novel interaction models for complex, multi-step AI workflows, enabling users to effectively guide, correct, and control AI actions.

• Translate sophisticated AI capabilities into intuitive and controllable user interfaces for everyday contexts across web and mobile platforms.

• Collaborate closely with product, engineering, and ML teams to rapidly iterate on concepts and deliver user-centered AI product features.

• Conduct user research and usability testing to identify friction points and enhance the reliability and transparency of AI-driven experiences.

📝 Enhancement Note: The role title "Product Designer (UX), HCI" and the description strongly indicate a focus on the intersection of user experience design and human-computer interaction, specifically within the context of advanced AI systems. The emphasis on "proactive AI," "long-running workflows," and "real-world task completion" suggests this is not a typical UI design role but one that requires deep thinking about how users interact with intelligent agents that perform actions. The "2-5 years" experience level suggests a mid-level individual contributor role.

📈 Primary Responsibilities

• Conceptualize, design, and execute end-to-end user experiences for AI-powered product surfaces, from initial ideation through to product launch and iteration.

• Define and prototype new interaction patterns for human-AI workflows, encompassing areas such as prompting, progress review, confirmation mechanisms, correction loops, task handoffs, and error recovery strategies.

• Develop interfaces that clearly communicate the AI's current state, its knowledge base, areas of uncertainty, and upcoming actions to foster user understanding and trust.

• Transform intricate, multi-step AI functionalities into user flows that are characterized by clarity, controllability, and ease of use in practical, day-to-day scenarios.

• Engage in cross-functional collaboration with product managers, engineers, and machine learning specialists to articulate problems, validate design hypotheses, and accelerate the development cycle.

• Produce comprehensive design artifacts, including user flows, wireframes, interactive prototypes, and high-fidelity mockups for both web and mobile applications.

• Lead and execute lightweight user research initiatives and usability testing sessions to uncover usability challenges, trust barriers, and potential failure points in AI interactions.

• Contribute to the establishment of a reusable design system by defining and documenting Human-AI Interaction (HCI) design patterns as the product and design system mature.

📝 Enhancement Note: The responsibilities listed are directly extracted from the provided description and are highly specific to designing interactions with AI systems. They emphasize the unique challenges of this domain, such as managing user trust, control, and understanding of AI actions, which goes beyond traditional UX design.

🎓 Skills & Qualifications

Education: While no specific degree is mandated, a background in Human-Computer Interaction (HCI), Interaction Design, Computer Science with a UX focus, or a related field is highly beneficial.

Experience: Minimum of 2-5 years of experience in product design, UX design, or interaction design, with a demonstrable track record of shipping web or mobile products.

Required Skills:

• Interaction Design: Proven ability to design intuitive and effective user flows and interactive experiences.

• Information Hierarchy: Skill in organizing complex information and features logically for optimal user comprehension.

• Prototyping: Proficiency in creating interactive prototypes to test and communicate design concepts.

• Figma Proficiency: Advanced skills in using Figma for design, wireframing, prototyping, and collaborative workflows.

• UX Design Principles: Strong understanding and application of core user experience design principles.

• Product Design Acumen: Experience in end-to-end product design, from concept to implementation.

• User Research & Usability Testing: Experience conducting user studies to gather feedback and validate design decisions.

• Wireframing: Ability to create clear and effective wireframes to map out user interfaces and flows.

• Human-AI Interaction (HCI): Foundational understanding or direct experience designing for AI-driven systems and user trust in AI.

• Mobile & Web Design: Experience designing for both mobile and web platforms.

Preferred Skills:

• Experience designing for AI products or systems with complex reasoning capabilities.

• Familiarity with ML concepts and how they influence user experience.

• Contribution to or experience with design systems.

• Experience in fast-moving, startup environments.

📝 Enhancement Note: The "What You Will Need" section directly translates into the required skills. The "2-5 years" experience level is inferred from the provided AI data point for "ai_experience_level". The preference for specific AI-related design experience is a logical extension of the role's focus.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• A comprehensive portfolio showcasing end-to-end product design projects, with a strong emphasis on complex interaction design and problem-solving.

• Specific case studies demonstrating how you've designed for AI-driven features or complex digital systems, highlighting your approach to user control, understanding, and trust.

• Examples of your work on both web and mobile platforms, illustrating your versatility across different device types.

Process Documentation:

• Showcase your ability to document user flows, interaction models, and design decisions clearly, especially for complex AI interactions.

• Provide examples of how you've used wireframes, prototypes, and high-fidelity designs to communicate your ideas effectively to engineering and product teams.

• Demonstrate your process for conducting user research and usability testing, including how you analyze findings and iterate on designs.

📝 Enhancement Note: This section is inferred based on standard expectations for Product Designer roles, especially those involving complex systems and AI, and the explicit mention of a portfolio in the interview process. The focus is on demonstrating problem-solving, process, and impact relevant to HCI and AI.

💵 Compensation & Benefits

Salary Range: £55,000 - £85,000 per annum (estimated)

Benefits:

• Competitive salary and equity options.

• Comprehensive health insurance coverage.

• Generous paid time off and holidays.

• Opportunities for professional development and learning.

• Remote work flexibility with potential for hybrid arrangements.

• Supportive and collaborative team environment.

Working Hours: Approximately 40 hours per week, with flexibility.

📝 Enhancement Note: The salary range is estimated based on industry benchmarks for mid-level Product Designers (2-5 years experience) in London, UK, considering the tech sector and the specialized HCI/AI focus. Benefits are typical for full-time tech roles in the UK, with an emphasis on professional growth and flexibility, aligning with the hybrid and remote aspects. The working hours are derived from the "ai_working_hours" field.

🎯 Team & Company Context

🏢 Company Culture

Industry: Technology / Artificial Intelligence / SaaS

Company Size: Small (Estimated 11-50 employees based on typical startup stages for this type of product)

Founded: The founding date is not provided, but the company is described as building a "proactive AI smart assistant," suggesting a focus on cutting-edge AI development.

Team Structure:

• A small, high-talent density, hands-on team.

• Collaborative decision-making with a focus on rapid execution.

Methodology:

• High-speed iteration and learning, balancing quality with rapid deployment.

• Emphasis on collective decision-making and independent execution.

• Deep focus on building a "truly magical product" that provides practical AI benefits.

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

📝 Enhancement Note: Company size is inferred based on the description of a "small, world-class team" and the nature of building a novel AI product, which often starts with lean teams. The methodology and team structure are directly extracted from the "How We Work" section.

📈 Career & Growth Analysis

Operations Career Level: This role is positioned as a mid-level Product Designer (UX/HCI), focusing on individual contribution and design execution within a specialized AI product domain. It offers the opportunity to shape foundational interaction paradigms for AI.

Reporting Structure: Likely reports to a Head of Design, Product Lead, or CTO, depending on the company's current structure. The emphasis on collective decision-making suggests a flat hierarchy where input is valued from all team members.

Operations Impact: The designer's work will directly influence the usability, adoption, and perceived value of the AI smart assistant. By defining how users interact with and control AI, the role has a significant impact on the product's success, user trust, and its ability to deliver practical benefits to a global user base.

Growth Opportunities:

• Specialization: Deepen expertise in Human-AI Interaction (HCI) and designing for complex AI systems, becoming a go-to expert in this emerging field.

• Leadership: As the company grows, opportunities may arise to lead design initiatives, mentor junior designers, or contribute to defining the broader product vision.

• Product Ownership: Take ownership of significant product areas, influencing strategy and roadmap based on user insights and design innovation.

• System Design: Contribute to the evolution of the company's design system, establishing reusable HCI patterns for AI.

📝 Enhancement Note: This analysis is based on the role's level, the company's description as a startup building a novel product, and general career progression paths within design and product development in the tech industry. The "operations" context is interpreted as the broader operational function of product development and strategy.

🌐 Work Environment

Office Type: The company offers a hybrid work model, allowing for remote work within the United Kingdom, with potential for in-office collaboration in London. This suggests a flexible approach to the work environment.

Office Location(s): London, England, United Kingdom. Specific office details are not provided, but the location indicates potential for in-person collaboration in a major tech hub.

Workspace Context:

• Collaborative Environment: The "How We Work" section emphasizes collective decision-making and making decisions collaboratively, implying a highly interactive and communicative workspace, whether remote or in-person.

• Technology & Tools: Access to industry-standard design tools like Figma is expected, along with potential exposure to AI/ML development tools and environments.

• Team Interaction: Opportunities for frequent interaction with product managers, engineers, and ML specialists to ensure seamless integration of design into the development lifecycle.

Work Schedule: A standard full-time schedule (approx. 40 hours/week) is expected, with an emphasis on flexibility to accommodate the demands of rapid iteration and cross-functional collaboration.

📝 Enhancement Note: The "Hybrid" and "Remote" status from the input data, combined with the London location, informs this section. The collaborative aspects are derived from the company's stated working methodology.

📄 Application & Portfolio Review Process

Interview Process:

• Application Submission: Candidates are required to submit an application, which must include a portfolio.

• Initial Screening: Applications and portfolios are reviewed by team members for initial fit.

• Interview Rounds (2): If a fit is identified, candidates will proceed to two rounds of interviews.

• Design Assessment: A design assessment will be part of the interview process, likely to evaluate practical design skills and problem-solving abilities related to HCI/AI.

• Virtual/Onsite Interviews: Interviews may be conducted virtually or onsite.

• Prompt Decision: The company aims for a transparent and efficient decision-making process.

Portfolio Review Tips:

• Highlight HCI/AI Focus: Ensure your portfolio prominently features projects demonstrating your ability to design for AI, manage user trust, and create clear interactions for complex systems.

• Showcase Process: Detail your design process, from research and ideation to iteration and final execution. Visualizing user flows and interaction patterns is key.

• Demonstrate Problem-Solving: Clearly articulate the challenges faced in your projects and how your design solutions addressed them, particularly for novel AI interaction problems.

• Include Figma Work: Showcase your proficiency in Figma, potentially including interactive prototypes or design system contributions.

• Quantify Impact: If possible, include metrics or qualitative feedback that demonstrate the positive impact of your designs.

Challenge Preparation:

• Understand the AI Domain: Familiarize yourself with current trends and challenges in AI interaction design, user trust in AI, and multi-step reasoning systems.

• Prepare for HCI Scenarios: Be ready to discuss how you would approach designing interfaces for AI that needs to explain its actions, handle errors gracefully, and allow for user correction.

• Case Study Practice: Practice presenting a past project as a case study, focusing on the problem, your unique contribution, the design decisions made, and the outcome.

📝 Enhancement Note: This section is derived directly from the "Interview process" section of the job description. The tips are tailored to the specific requirements of a Product Designer role focused on AI and HCI.

🛠 Tools & Technology Stack

Primary Tools:

• Figma: Essential for wireframing, prototyping, UI design, and collaborative workflows.

• Prototyping Tools: Beyond Figma, any other preferred prototyping tools for advanced interactions.

• User Research Tools: Tools for conducting usability testing and gathering user feedback (e.g., Lookback, UserTesting.com, Maze).

Analytics & Reporting:

CRM & Automation:

• Not directly relevant to this design role, but an understanding of how design integrates with the broader product development lifecycle, including CRM and automation tools used by sales/marketing, can be helpful for context.

📝 Enhancement Note: Figma is explicitly mentioned. Other tools are inferred based on standard practices for product designers, particularly those involved in user research and rapid prototyping.

👥 Team Culture & Values

Operations Values:

• High Talent Density & Hands-On Approach: The team values individuals who are exceptionally skilled and willing to contribute directly and actively.

• Collective Decision-Making: Decisions are made as a group, fostering a sense of shared ownership and collaboration.

• Rapid Speed & Learning: A culture that embraces quick iteration, learning from mistakes, and continuous improvement.

• Judgment & Independent Execution: While collaborative, individuals are expected to exercise sound judgment and execute tasks independently.

• Building Magical Products: A shared ambition to create truly exceptional and impactful products.

Collaboration Style:

• Cross-functional Integration: Close collaboration with Product, Engineering, and ML teams is fundamental to the workflow.

• Feedback Exchange: An open environment for giving and receiving feedback to drive quality and innovation.

• Knowledge Sharing: Encouraging the sharing of insights, best practices, and learnings across the team.

📝 Enhancement Note: These values and collaboration styles are directly extracted and synthesized from the "How We Work" section of the job description.

⚡ Challenges & Growth Opportunities

Challenges:

• Defining Novel Interaction Paradigms: Creating entirely new ways for humans to interact with sophisticated, multi-step AI systems, moving beyond existing UX patterns.

• Building Trust in AI: Designing interfaces that effectively foster user trust, transparency, and a sense of control over AI actions, especially in critical workflows.

• Managing Ambiguity: Working in a fast-paced startup environment where requirements may evolve, requiring designers to shape solutions from incomplete information.

• Balancing Complexity and Simplicity: Translating complex AI capabilities into simple, intuitive, and controllable user experiences.

Learning & Development Opportunities:

• Specializing in AI/HCI: Gaining deep expertise in the rapidly evolving field of AI interaction design and Human-AI Collaboration.

• Product Strategy Influence: Contributing to the strategic direction of an innovative AI product and shaping its user experience roadmap.

• Working with Cutting-Edge Technology: Hands-on experience with AI, machine learning, and advanced reasoning systems.

• Startup Growth Experience: Participating in the growth and scaling of a tech startup.

📝 Enhancement Note: Challenges and growth opportunities are inferred based on the nature of the product (AI smart assistant), the role's focus (HCI, novel interactions), and the company context (startup).

💡 Interview Preparation

Strategy Questions:

• AI Interaction Design Philosophy: Be prepared to discuss your approach to designing for AI, focusing on trust, transparency, control, and explainability. How do you move beyond traditional UI patterns?

• HCI Case Study Presentation: Have a compelling case study ready that showcases your ability to tackle complex interaction problems, ideally involving AI or multi-step processes. Focus on your thought process and design decisions.

• Handling Ambiguity: Discuss how you approach design challenges when requirements are not fully defined. Provide examples of how you've brought structure to ambiguous problems.

Company & Culture Questions:

• AI Product Vision: Research Bjak's mission and product. Be ready to discuss your thoughts on how AI can benefit everyday users and what makes a "magical" AI product.

• Collaboration Style: Prepare to talk about your experience working with engineering and ML teams, and how you foster effective cross-functional collaboration.

• Design System Contribution: If you have experience building or contributing to design systems, be ready to discuss it, especially regarding reusable HCI patterns.

Portfolio Presentation Strategy:

• Narrative Arc: Structure your portfolio presentation around clear narratives for each project, highlighting the problem, your unique contribution, the design process, key decisions, and the outcome/impact.

• Focus on HCI Elements: For AI-focused projects, explicitly call out how you addressed user trust, control, AI explainability, and error handling.

• Showcase Figma Skills: Be ready to walk through specific Figma files or prototypes to demonstrate your interaction design and prototyping capabilities.

• Conciseness and Clarity: Present your work clearly and concisely, respecting the interviewer's time.

📝 Enhancement Note: These questions and strategies are tailored to the specific requirements of the Product Designer (UX), HCI role at Bjak, emphasizing the AI and interaction design aspects.

📌 Application Steps

To apply for this Product Designer position:

• Submit your application through the provided link on Ashby.

• Portfolio Customization: Tailor your portfolio to highlight relevant projects, especially those involving complex interactions, AI, or innovative user experiences. Ensure it clearly demonstrates your skills in Figma, interaction design, and problem-solving.

• Resume Optimization: Update your resume to emphasize experience in product design, UX/HCI, working with engineering teams, and any exposure to AI or complex system design. Use keywords from the job description.

• Interview Preparation: Practice articulating your design process and decision-making for a variety of scenarios, with a focus on HCI and AI challenges. Prepare to present your portfolio effectively.

• Company Research: Familiarize yourself with Bjak's mission, product vision, and the "How We Work" ethos to demonstrate your understanding of their culture and goals.

⚠️ 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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