Senior UI Engineer (Belfast, UK)

📍 Job Overview

Job Title: Senior UI Engineer

Company: Congruity360

Location: Belfast, Northern Ireland, United Kingdom

Job Type: Full-Time

Category: Technology / Engineering / Frontend Development

Date Posted: 2026-10-01

Experience Level: 5-10 Years

Remote Status: Hybrid (minimum 2 days per week in office)

🚀 Role Summary

• Develop intuitive and high-quality user interfaces for a new cybersecurity product offering, expanding Congruity360's solution set beyond compliance and data governance.

• Drive technical decisions within a dynamic engineering team, contributing to the strategic direction of the product's frontend architecture and implementation.

• Collaborate closely with UX designers and product managers to translate complex customer needs and technical requirements into seamless and user-friendly interfaces.

• Focus on building accessible, responsive, and performant user experiences, adhering to best practices in UI development and modern web standards.

• Leverage emerging technologies and a primary React skillset to create innovative solutions that enhance the client experience and provide superior product functionality.

📝 Enhancement Note: This role is crucial for the development of a new cybersecurity product, indicating a significant opportunity for impact and innovation in a growing area for Congruity360. The emphasis on "emerging technologies" and "driving technical decisions" suggests a high degree of autonomy and influence for the successful candidate.

📈 Primary Responsibilities

• Design, develop, and implement robust, scalable, and maintainable frontend features using React, TypeScript, and JavaScript, with a strong emphasis on code quality and best practices.

• Translate wireframes, mockups, and product requirements into functional, accessible, and responsive user interfaces, ensuring a consistent and superior client experience.

• Collaborate with cross-functional teams, including UX/UI designers, product managers, and backend engineers, to define technical specifications and deliver cohesive product solutions.

• Optimize frontend performance for complex interfaces and large datasets, ensuring fast load times, smooth interactions, and efficient data handling.

• Contribute to the architectural design and technical roadmap for the new cybersecurity product's frontend, including decisions on component libraries, state management, and API integrations.

• Implement and maintain accessibility standards (WCAG) and semantic HTML to ensure all users can effectively interact with the product.

• Develop and refine reusable UI components and potentially contribute to design systems to promote consistency and efficiency across the application.

• Consume and shape REST APIs, managing state effectively for complex, long-lived workspaces to ensure data integrity and seamless user workflows.

• Actively participate in code reviews, providing constructive feedback to peers and upholding high standards for code quality, security, and performance.

• Stay abreast of emerging frontend technologies and industry trends, evaluating and recommending new tools and techniques to enhance product development and user experience.

📝 Enhancement Note: The responsibilities highlight a blend of hands-on development, architectural input, and cross-functional collaboration. The emphasis on "data-rich interfaces," "large tables, charts and visualisations," and "frontend performance optimisation" points to a need for expertise in handling complex data presentation and ensuring a fluid user experience, especially relevant for cybersecurity and data governance tools.

🎓 Skills & Qualifications

Education: A University degree (or equivalent) in Computer Science, Mathematics, Physics, or a related field is required.

Experience: 5+ years of relevant software engineering and development experience, with a proactive attitude, excellent communication skills, strong attention to detail, self-motivation, and the ability to work effectively within a team.

Required Skills:

• 5+ years of professional experience with TypeScript and JavaScript.

• 3+ years of hands-on experience with React for building complex user interfaces.

• Proven UX experience, including effective collaboration with designers and product managers to translate requirements into intuitive interfaces.

• Practical knowledge of Web Content Accessibility Guidelines (WCAG) and semantic HTML for building accessible web applications.

• Experience with modern component libraries such as React Aria or Radix, and CSS frameworks like Tailwind CSS or comparable solutions.

• Demonstrated experience in developing data-rich interfaces, including proficiency with large tables, charts, and visualisations.

• Expertise in frontend performance optimization techniques, particularly for complex interfaces and large datasets.

• Experience consuming and shaping REST APIs, with strong proficiency in state management for complex, long-lived workspaces. Preferred Skills:

• Experience in enterprise software development environments.

• Advanced skills in charting, data visualization, and virtualization using tools like D3, visx, ECharts, or TanStack Table.

• Experience in architectural design, particularly in designing new products or systems from the ground up.

• Proven ability to build and maintain reusable component libraries and design systems.

• Familiarity with cybersecurity concepts, analyst tooling, audit trails, and role-based access controls.

• Exposure to CI/CD pipelines and cloud platforms such as AWS or Azure.

• Experience with Node.js development.

• Experience with Vue.js.

• Practical experience working in Agile, cross-functional delivery teams.

📝 Enhancement Note: The required skills emphasize a strong foundation in modern frontend technologies, particularly React, and a deep understanding of user experience, accessibility, and performance. The preferred skills suggest opportunities for candidates with broader architectural vision, specialized data visualization expertise, and experience in enterprise or security-focused software development.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Showcase projects demonstrating proficiency in building complex, data-rich user interfaces using React and TypeScript.

• Include examples of accessible and responsive UI development, highlighting adherence to WCAG standards and semantic HTML best practices.

• Present case studies of frontend performance optimization, detailing challenges faced and the strategies implemented to improve interface speed and responsiveness.

• Provide examples of effective state management for complex applications and successful integration with RESTful APIs.

• Demonstrate experience with component libraries and CSS frameworks, illustrating how they were used to create efficient and maintainable UI solutions. Process Documentation:

• Document the process of translating UX/UI designs and product requirements into functional frontend code, emphasizing collaboration and iterative development.

• Illustrate the approach to performance profiling and optimization, including tools and methodologies used to identify and resolve bottlenecks.

• Detail the workflow for API integration and state management, explaining how complex data flows and user interactions were handled.

• Outline the process for ensuring accessibility and responsiveness across different devices and user scenarios.

📝 Enhancement Note: A strong portfolio is critical for this role. Candidates should be prepared to articulate their design process, problem-solving methodologies, and the technical decisions behind their projects, particularly those involving complex data visualization and performance-critical interfaces.

💵 Compensation & Benefits

Salary Range: Negotiable. Based on industry benchmarks for Senior UI Engineers in the UK with 5-10 years of experience, the estimated range could be between £55,000 - £75,000 per annum. This is dependent on the candidate's specific experience, skills, and interview performance.

Benefits:

• Pension scheme to support long-term financial planning.

• Flexible working hours and hybrid work options, offering a balance between remote work and in-office collaboration.

• Health insurance and wellness programs to support employee well-being.

• Generous holiday leave and paid time off to encourage work-life balance.

• Flexible working policy to accommodate diverse working styles and needs.

• Volunteer policy, encouraging employees to contribute to their communities.

Working Hours: The role is full-time, with flexible working hours. A minimum of 2 days per week is required in the Belfast office, aligning with a hybrid work model. Standard full-time hours are typically 37.5-40 hours per week, but flexibility is provided.

📝 Enhancement Note: The "Negotiable" salary indicates that Congruity360 is open to offering competitive compensation based on the candidate's qualifications. The comprehensive benefits package, including flexible working and wellness programs, points to a company culture that values employee well-being and work-life balance. Researching local Belfast salary benchmarks for similar roles is recommended.

🎯 Team & Company Context

🏢 Company Culture

Industry: Software & Technology, specifically focused on Data Governance, Compliance, and emerging Cybersecurity solutions. Congruity360 aims to help clients reduce financial and data risk by improving data understanding, classification, and security.

Company Size: Congruity360 has a presence across the US, England, and Northern Ireland, suggesting a mid-sized to large organization with international operations. This size often implies established processes but also opportunities for individual impact.

Founded: The company's founding date is not specified, but its focus on both established (data governance) and emerging (cybersecurity) solutions indicates a company that evolves with market demands.

Team Structure:

• The Engineering department is responsible for product development.

• This Senior UI Engineer role reports to a Team Lead within Engineering.

• Collaboration is expected with UX designers, product managers, and backend engineers, indicating a cross-functional team approach. Methodology:

• The company emphasizes making intelligent business decisions through data understanding and classification, suggesting a data-driven approach.

• The development environment is described as "fast-paced," "coding in a fast-paced development environment," and focused on "generating creative solutions."

• Agile methodologies are implied through the "Agile, cross-functional delivery" preferred criterion.

Company Website: https://www.congruity360.com/

📝 Enhancement Note: Congruity360 operates in a critical B2B software space, providing solutions that manage data risk and security. The new cybersecurity product initiative suggests a forward-thinking approach to market needs. The culture appears to value innovation, problem-solving, and collaboration, with a global reach but a local presence in Belfast.

📈 Career & Growth Analysis

Operations Career Level: This is a Senior-level position within the UI Engineering track. It signifies a lead contributor role responsible for complex tasks, technical decision-making, and potentially mentoring junior engineers. The focus on a new product launch indicates a high-impact role with significant ownership.

Reporting Structure: The role reports to a Team Lead, suggesting a clear hierarchical structure within the engineering department. This provides a direct line for guidance, feedback, and career development discussions.

Operations Impact: As a Senior UI Engineer on a new product, the impact is substantial. The candidate will directly influence the user experience, product adoption, and ultimately the success of Congruity360's expansion into the cybersecurity market. High-quality UI is critical for customer satisfaction and market competitiveness in enterprise software.

Growth Opportunities:

• Technical Specialization: Deepen expertise in React, data visualization, accessibility, and performance optimization. Potential to become a subject matter expert in these areas.

• Architectural Leadership: Grow into a role with more significant architectural responsibilities, leading the design of new frontend systems or major features.

• Team Leadership: Develop leadership skills and potentially move into a formal Team Lead or management position, mentoring other engineers and guiding team strategy.

• Product Expansion: Gain experience in launching and iterating on new product lines within a growing company.

• Cross-functional Expertise: Broaden understanding of cybersecurity, data governance, and enterprise software domains through close collaboration.

📝 Enhancement Note: The Senior UI Engineer role at Congruity360 offers a strong career trajectory, especially given the opportunity to shape a new product. The combination of technical depth and potential for leadership makes it an attractive position for ambitious engineers looking for significant impact and professional development.

🌐 Work Environment

Office Type: Hybrid work model, requiring a minimum of 2 days per week in the Belfast office. This suggests a modern office setup designed to facilitate collaboration and team interaction, balanced with the flexibility of remote work.

Office Location(s): Belfast, Northern Ireland (BT2 8FE). This central location likely offers good accessibility for local employees.

Workspace Context:

• Collaborative Environment: The hybrid model necessitates a workspace that supports both individual focused work and team collaboration. Expect meeting rooms, breakout spaces, and potentially open-plan areas.

• Technology & Tools: Access to modern development tools, high-performance workstations, and potentially specialized hardware or software for UI development and testing.

• Team Interaction: Opportunities for face-to-face interaction with colleagues, fostering team cohesion, knowledge sharing, and spontaneous problem-solving sessions.

Work Schedule: Full-time with flexible working hours. The hybrid requirement of 2 days in the office provides structure, while flexible hours allow for better personal time management, which can be beneficial for focused coding sessions or accommodating personal commitments.

📝 Enhancement Note: The hybrid model in Belfast indicates a company that is adapting to modern work trends, aiming to balance employee flexibility with the benefits of in-person collaboration. Candidates should expect a professional, technology-focused environment conducive to complex software development.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: Review of CV and application, likely followed by a brief call with HR or a recruiter to assess basic qualifications and cultural fit.

• Technical Assessment: This may involve a coding challenge (e.g., a take-home project or live coding exercise focusing on React, TypeScript, and UI principles) or a technical interview discussing past projects and problem-solving approaches.

• Portfolio Review: A dedicated session where candidates present their portfolio, explaining their contributions, technical decisions, and the impact of their work. Expect deep dives into specific projects, focusing on UI architecture, performance, and accessibility.

• Team/Hiring Manager Interview: Discussion with the Team Lead and potentially other senior engineers or product managers. This interview will focus on technical depth, problem-solving skills, collaboration style, and alignment with team and company values.

• Final Interview: Potentially a discussion with senior leadership or a final confirmation interview.

Portfolio Review Tips:

• Curate Selectively: Choose 2-3 of your strongest projects that best showcase your skills in React, TypeScript, UI/UX, performance optimization, and data-rich interfaces.

• Quantify Impact: For each project, clearly articulate your specific contributions, the challenges you overcame, the technical solutions you implemented, and the measurable outcomes (e.g., performance improvements, user satisfaction metrics, efficiency gains).

• Explain Technical Decisions: Be prepared to articulate why you made certain architectural choices, library selections, or implementation strategies. Discuss trade-offs considered.

• Demonstrate Process: Walk through your development process, from understanding requirements to final implementation and testing. Highlight collaboration with designers and product managers.

• Focus on Relevance: Emphasize projects that align with Congruity360's focus on enterprise software, data visualization, and potentially cybersecurity.

Challenge Preparation:

• Core React Concepts: Refresh your understanding of React hooks, component lifecycle, state management (e.g., Context API, Redux, Zustand), performance optimization techniques (memoization, lazy loading), and efficient rendering.

• TypeScript Mastery: Be ready to demonstrate strong TypeScript skills, including type definitions, interfaces, generics, and best practices for building robust applications.

• UI/UX Principles: Review principles of accessible design (WCAG), responsive design, semantic HTML, and user-centered design thinking.

• Problem-Solving: Practice breaking down complex UI problems, designing solutions, and articulating your thought process clearly and concisely.

• Data Visualization: If you have experience, prepare to discuss approaches to handling large datasets, charting libraries, and creating performant visualizations.

📝 Enhancement Note: The interview process emphasizes both technical proficiency and the ability to articulate one's contributions and decision-making processes. A well-prepared portfolio presentation is paramount for demonstrating the required skills and experience effectively.

🛠 Tools & Technology Stack

Primary Tools:

• JavaScript/TypeScript: Core programming languages for frontend development.

• React: The primary framework for building user interfaces.

• State Management Libraries: Tools like Context API, Redux, Zustand, or Jotai for managing complex application state.

• Component Libraries: React Aria, Radix, or similar for building accessible and reusable UI components.

• CSS Frameworks: Tailwind CSS or comparable for efficient styling and theming.

• Build Tools: Webpack, Vite, or similar for bundling and optimizing frontend assets.

• Version Control: Git for source code management.

Analytics & Reporting:

• Frontend Performance Monitoring Tools: Lighthouse, WebPageTest, or integrated APM tools for analyzing and improving application performance.

• Browser Developer Tools: Essential for debugging, performance profiling, and inspecting UI elements.

CRM & Automation: While not explicitly mentioned for the UI Engineer role, awareness of how the frontend interacts with backend systems and potentially data governance or security platforms is beneficial.

📝 Enhancement Note: Proficiency in the React ecosystem, including TypeScript, modern CSS solutions, and state management, is essential. Familiarity with tools for performance optimization and accessibility is also critical. Experience with data visualization libraries and potentially enterprise software development stacks would be advantageous.

👥 Team Culture & Values

Operations Values:

• Quality & Craftsmanship: A drive to produce high-quality, well-engineered software that provides a superior client experience.

• Innovation & Creativity: Encouraging the generation of creative solutions to solve customer needs and challenges, especially in new product development.

• Collaboration & Teamwork: Working effectively within a dynamic team, sharing knowledge, and contributing to collective success.

• Customer Focus: A commitment to understanding and meeting customer needs through intuitive interfaces and robust functionality.

• Proactiveness & Ownership: Taking initiative, demonstrating a proactive attitude, and owning tasks from conception to completion.

Collaboration Style:

• Cross-functional Integration: Close collaboration with UX designers and product managers to ensure alignment between design, functionality, and technical feasibility.

• Agile Development: Working within cross-functional, Agile teams to deliver software iteratively and adapt to changing requirements.

• Knowledge Sharing: A culture that likely encourages code reviews, pair programming, and open discussions to share best practices and solve complex problems collectively.

📝 Enhancement Note: Congruity360 appears to value a blend of technical excellence, innovative problem-solving, and collaborative teamwork. The emphasis on client experience and proactive contribution suggests a results-oriented environment where engineers are empowered to make a difference.

⚡ Challenges & Growth Opportunities

Challenges:

• Building a New Product: The primary challenge will be contributing to the development of a new cybersecurity product from its early stages, requiring adaptability, problem-solving, and the ability to define and implement features with potentially evolving requirements.

• Complex Data Interfaces: Designing and optimizing interfaces for complex data, large tables, and visualizations can be technically demanding, requiring careful attention to performance and usability.

• Balancing Innovation with Stability: Integrating emerging technologies while ensuring the stability, security, and maintainability of enterprise-grade software.

• Hybrid Work Dynamics: Effectively collaborating and maintaining team cohesion within a hybrid work environment.

Learning & Development Opportunities:

• Deepen React Expertise: Gain advanced skills in React, its ecosystem, and modern frontend architecture patterns.

• Master Data Visualization: Develop specialized skills in creating sophisticated and performant data visualizations for complex datasets.

• Contribute to Architecture: Influence the technical direction and architectural decisions for a new product line.

• Cybersecurity Domain Knowledge: Acquire valuable insights into the cybersecurity domain through product development.

• Mentorship: Opportunity to mentor junior engineers and grow into a leadership role.

📝 Enhancement Note: This role presents significant growth potential by tackling new product development challenges and deepening expertise in specialized frontend areas. The company's focus on evolving solutions suggests a dynamic learning environment.

💡 Interview Preparation

Strategy Questions:

• "Describe a complex UI you've built that involved handling large datasets or intricate visualizations. What were the key challenges, and how did you optimize performance and user experience?" (Focus on React, data handling, performance optimization, and problem-solving.)

• "How do you approach translating UX/UI designs and product requirements into functional, accessible, and responsive frontend code? Walk me through your process." (Highlight collaboration, adherence to standards like WCAG, and translation of requirements.)

• "Discuss a time you had to drive a technical decision within your team regarding frontend architecture or technology choices. What was the situation, and what was the outcome?" (Demonstrate leadership, technical reasoning, and impact.) Company & Culture Questions:

• "What interests you about Congruity360's expansion into cybersecurity, and how do you see your UI engineering skills contributing to this new product?" (Show research into the company and product, and connect your skills to their goals.)

• "How do you envision collaborating with UX designers and product managers in a hybrid work environment to ensure a cohesive product experience?" (Address collaboration style, communication strategies, and adaptability to hybrid work.)

• "Describe your experience with building reusable component libraries or design systems. What are the benefits and challenges?" (Gauge experience with scalable UI development and efficiency.) Portfolio Presentation Strategy:

• Storytelling: Structure your portfolio presentation as a narrative for each project, detailing the problem, your solution, your role, the technical approach, and the results.

• Visuals: Use clear, concise visuals (screenshots, demos, diagrams) to illustrate your work and technical concepts.

• Metrics: Quantify your achievements with data whenever possible (e.g., "improved load time by X%", "reduced rendering time by Y ms," "achieved 100% WCAG AA compliance").

• Technical Depth: Be ready to answer detailed questions about your code, architectural choices, and the technologies you used. Explain why you made those decisions.

• Conciseness: Respect the allocated time. Focus on the most impactful aspects of your projects that align with the job requirements.

📝 Enhancement Note: Candidates should prepare to showcase not only their technical skills but also their strategic thinking, problem-solving abilities, and collaborative approach. Demonstrating a clear understanding of the company's mission and the role's impact will be crucial.

📌 Application Steps

To apply for this Senior UI Engineer position:

• Submit your application through the provided link on the Congruity360 careers portal.

• Tailor Your CV: Ensure your resume highlights your 5+ years of JavaScript/TypeScript experience and 3+ years of React expertise, along with specific achievements in UI development, performance optimization, and accessibility. Use keywords from the job description.

• Prepare Your Portfolio: Curate a selection of your strongest projects that demonstrate your skills in React, data-rich interfaces, and performance optimization. Be ready to present and discuss them in detail, focusing on your contributions and the impact of your work.

• Research Congruity360: Understand the company's mission, its existing products (Classify360), and the strategic importance of its new cybersecurity offering. This will help you tailor your responses during interviews.

• Practice Interview Questions: Prepare to answer technical questions about React, TypeScript, UI/UX principles, and performance optimization, as well as behavioral questions about collaboration, problem-solving, and technical decision-making.

⚠️ 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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