UI / UX & API Enwtwickler mit KI & Claude Erfahrung (m/w/d)

📍 Job Overview

Job Title: UI / UX & API Developer with AI & Claude Experience (m/f/d)

Company: Pakajo GmbH

Location: Hamburg, Germany

Job Type: Full-time

Category: Software Development / Engineering

Date Posted: June 6, 2026

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

Remote Status: Hybrid

🚀 Role Summary

• Spearhead the design and development of a cutting-edge, user-centric interface for an AI-powered comparison and shipping portal.

• Drive the integration of advanced AI technologies, specifically Claude, into the frontend architecture to enhance user experience and functionality.

• Develop and optimize robust APIs that support seamless data exchange and system integrations within the eCommerce logistics ecosystem.

• Collaborate closely with cross-functional teams, including product development and marketing, to translate business requirements into intuitive and efficient digital solutions.

• Focus on continuous improvement of web application performance, speed, and overall user satisfaction through iterative design and development cycles.

📝 Enhancement Note: While the title specifies "UI/UX & API Developer," the core responsibilities and company mission strongly suggest a role deeply embedded within the product development team, focusing on building and enhancing the user-facing aspects of their innovative eCommerce shipping platform. The emphasis on AI and Claude integration points towards a strategic role in leveraging emerging technologies to create a competitive advantage.

📈 Primary Responsibilities

• Design, develop, and implement intuitive and engaging user interfaces (UI) for Pakajo's AI-driven comparison and shipping portal, ensuring a seamless and positive user experience (UX).

• Translate complex user needs and business requirements into functional and aesthetically pleasing frontend designs and interactive prototypes.

• Develop, test, and maintain efficient and scalable APIs to facilitate data flow between frontend, backend systems, and third-party integrations.

• Integrate Artificial Intelligence (AI) capabilities, with a specific focus on Claude, into the frontend to power features such as intelligent tracking, personalized recommendations, and automated support.

• Optimize web application performance, focusing on speed, responsiveness, and scalability across various devices and browsers to ensure optimal user engagement.

• Conduct user research, usability testing, and gather feedback to iterate on designs and improve the overall user journey and product functionality.

• Collaborate with backend developers, product managers, and designers to define API specifications, ensure data integrity, and deliver integrated solutions.

• Stay abreast of the latest trends in UI/UX design, API development, and AI technologies to propose and implement innovative enhancements.

• Ensure the portal's optimal display and functionality across different end-user devices and platforms.

📝 Enhancement Note: The responsibilities list emphasizes both frontend design and API development, indicating a full-stack capability within the UI/UX domain. The explicit mention of "AI-gestütztes Vergleichs- und Versandportal" and "KI-Tracking-Tool" highlights the critical nature of AI integration, making "Claude" experience a key differentiator.

🎓 Skills & Qualifications

Education:

• Bachelor's degree in Computer Science, Design, Information Technology, or a related field, or equivalent practical experience. Experience:

• Minimum of 3 years of professional experience in UI/UX design and API development/integration.

• Proven track record of designing and implementing user-friendly web interfaces and functional APIs. Required Skills:

• UI/UX Design: Expertise in user-centered design principles, wireframing, prototyping, and creating visually appealing interfaces.

• API Development & Integration: Strong understanding of RESTful API design, implementation, and integration.

• Frontend Technologies: Proficient in PHP and JavaScript, with experience in modern frontend frameworks (e.g., React, Vue, Angular - inferred based on standard industry practices for dynamic web portals).

• AI & Machine Learning Concepts: Demonstrated experience working with AI technologies, specifically with LLMs like Claude, for practical application in user-facing features.

• Responsive Design: Ability to ensure optimal portal display and functionality across various devices (desktop, tablet, mobile).

• Web Performance Optimization: Skills in improving website speed, loading times, and overall performance.

• Cross-functional Collaboration: Excellent communication and interpersonal skills to work effectively with diverse teams.

Preferred Skills:

• Experience with specific JavaScript frameworks like React, Vue.js, or Angular for building complex, dynamic user interfaces.

• Familiarity with CI/CD pipelines and version control systems (e.g., Git).

• Knowledge of backend development languages or frameworks for a more comprehensive understanding of the tech stack.

• Experience with A/B testing and data-driven design iterations.

• Understanding of eCommerce logistics and shipping processes.

📝 Enhancement Note: The explicit mention of "PHP und Javascript" in the description, combined with the need for a dynamic portal and AI integration, strongly suggests that experience with modern JavaScript frameworks is highly beneficial, even if not explicitly listed. The "Mindestens 3 Jahre Berufserfahrung" indicates a mid-level role, requiring demonstrable project experience.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Showcase at least two distinct UI/UX design projects, demonstrating your process from concept to final implementation, with a focus on user research and problem-solving.

• Present a minimum of one API integration project, detailing its purpose, the technologies used, and the impact it had on system functionality or efficiency.

• Include examples of UI elements or components that highlight your attention to detail, usability, and aesthetic design principles.

• Demonstrate experience with AI integration, ideally showcasing how you've leveraged AI (like Claude) to enhance user experience or automate processes within a digital product.

• Provide case studies that clearly articulate the challenges faced, the solutions implemented, and the measurable outcomes achieved in your projects. Process Documentation:

• Be prepared to discuss your design process, including user research methodologies, wireframing tools, prototyping techniques, and usability testing approaches.

• Articulate your API development lifecycle, from requirements gathering and design to implementation, testing, and ongoing maintenance.

• Explain your approach to integrating AI models, including data handling, prompt engineering, and validating model outputs within a user-facing application context.

• Document your workflow for optimizing web application performance, detailing the tools and strategies used to identify bottlenecks and improve loading speeds.

📝 Enhancement Note: For a UI/UX and API Developer role, a portfolio is crucial. It should not only display visual design but also demonstrate technical competence in API development and, critically for this role, practical application of AI, especially Claude. The emphasis on "user-centered designs" and "usability tests" means the portfolio needs to show how user feedback shaped the final product.

💵 Compensation & Benefits

Salary Range:

• Based on the provided salary of €43,000 per year for this role in Hamburg, Germany, and considering the mid-level experience requirement (3+ years) and specialized skills (UI/UX, API, AI/Claude), this falls within the expected range for a junior to mid-level developer in this metropolitan area. However, for a candidate with 3+ years of experience and strong AI/Claude expertise, the market rate in Hamburg could potentially range from €45,000 to €60,000 annually, depending on the depth of their AI and API integration skills. Benefits:

• Innovative and forward-looking work environment in a dynamic team.

• Exciting projects and the opportunity to contribute to the development of pioneering technologies.

• Flexible working hours model.

• Partial remote work options available.

• Opportunities for further training and support for professional development.

• Attractive salary package and additional benefits.

• Free drinks and subsidized meals.

• Proximity to public transport (2 minutes walk to S-Bahn station).

• A young, dynamic, and innovative work environment within an award-winning company.

• The chance to actively contribute to the company's success. Working Hours:

• The standard working hours are approximately 40 hours per week, with a flexible working time model and partial remote work options, offering a good work-life balance.

📝 Enhancement Note: The stated salary of €43,000 is noted. For a role in Hamburg requiring 3+ years of experience and specialized AI/Claude skills, this might be on the lower end of the market rate for a mid-level developer. The listed benefits are comprehensive and attractive, especially the flexibility and professional development aspects.

🎯 Team & Company Context

🏢 Company Culture

Industry: Technology, Information & Internet (specifically focusing on eCommerce logistics and shipping comparison).

Company Size: Small to Medium-sized Enterprise (SME) - based on typical startup growth phases and team dynamics implied.

Founded: Pakajo GmbH is presented as an innovative, award-winning company ("preisgekrönten Arbeitgeber der Zukunft und Digital Start-Up Champion"), suggesting a relatively young but rapidly growing organization.

Team Structure:

• The role involves close collaboration with an international team of developers, designers, product managers, and marketing specialists.

• You will be part of a dynamic, agile development environment focused on innovation and rapid iteration.

• The reporting structure is likely to be within a product development or engineering team, with a direct lead or manager overseeing the UI/UX and API development efforts. Methodology:

• Pakajo emphasizes innovation, teamwork, and social responsibility as core values.

• The development approach likely involves agile methodologies (e.g., Scrum, Kanban) to facilitate rapid development and adaptation.

• A strong focus on user-centricity, data-driven decision-making, and continuous improvement is evident in the role's responsibilities.

• The company aims to create the "world's largest comparison and shipping portal for eCommerce shipping," indicating a strong focus on scalability and market leadership.

Company Website: https://pakajo.world

📝 Enhancement Note: The company description highlights its ambition to become a leading player in eCommerce shipping solutions, powered by AI. This suggests a fast-paced, growth-oriented environment where innovation and agility are paramount. The "international team" aspect implies a diverse and potentially remote-friendly work culture.

📈 Career & Growth Analysis

Operations Career Level: This role is positioned as a Mid-Level Developer ("Mindestens 3 Jahre Berufserfahrung"). It requires a solid foundation in UI/UX design and API development, with a specific emphasis on practical application of AI technologies. The individual will be expected to work somewhat independently on feature development and contribute significantly to product design and technical implementation.

Reporting Structure: The role likely reports to a Lead Developer, Engineering Manager, or Head of Product. Collaboration will be extensive with designers, product managers, and other engineers (frontend and backend).

Operations Impact: As a UI/UX & API Developer, the impact is direct and significant:

• User Experience: Directly shapes how customers interact with the platform, influencing satisfaction, retention, and conversion rates.

• Platform Functionality: Develops the core interface and data pathways, enabling critical features like comparison, booking, and tracking.

• AI Integration: Drives the adoption and effectiveness of AI tools like Claude, differentiating the platform through intelligent features.

• Efficiency: Optimizes performance and streamlines workflows through well-designed interfaces and robust APIs, contributing to operational efficiency for both users and the company.

Growth Opportunities:

• Technical Specialization: Deepen expertise in AI integration, LLMs (like Claude), advanced UI/UX patterns, and specific API design principles.

• Full-Stack Development: Expand skills into backend development, database management, or cloud infrastructure.

• Team Leadership: Progress to a Senior Developer, Tech Lead, or even a management role within the product development team as the company scales.

• Product Ownership: Transition into Product Management roles, leveraging technical understanding to define product strategy and roadmaps.

• Industry Expertise: Become a subject matter expert in eCommerce logistics technology, a rapidly growing and evolving field.

📝 Enhancement Note: The role offers a clear path for growth from a mid-level individual contributor. The emphasis on AI and emerging technologies provides an excellent opportunity to build in-demand skills that are highly valuable in the current tech landscape, especially within the booming eCommerce sector.

🌐 Work Environment

Office Type: The description mentions an "innovatives und zukunftsweisendes Arbeitsumfeld" and being an "award-winning company." This suggests a modern, collaborative, and potentially open-plan office space designed to foster creativity and teamwork. The proximity to public transport ("2 min Gehweg vom Büro zu S-Bahn") indicates an accessible and well-connected urban location.

Office Location(s): Hamburg, Germany. Specifically, the office is conveniently located near an S-Bahn station, making it easily accessible for commuters.

Workspace Context:

• Collaborative Environment: Expect a dynamic team setting where open communication, idea sharing, and cross-functional collaboration are encouraged.

• Tools & Technology: Access to modern development tools and technologies required for UI/UX design, API development, and AI integration. This will likely include design software, IDEs, testing frameworks, and potentially AI development platforms.

• Team Interaction: Opportunities to engage with a diverse, international team, fostering a rich learning and exchange environment. The "young, dynamic and innovative work environment" implies a culture that values contribution and open dialogue.

Work Schedule: The role offers flexible working hours and partial remote work options, allowing for a good balance between in-office collaboration and personal work preferences. This flexibility is crucial for developers to manage focus time and deep work effectively.

📝 Enhancement Note: The hybrid work model combined with flexible hours suggests a company that trusts its employees and prioritizes a productive work environment that accommodates individual needs. The emphasis on being an "award-winning employer" hints at a positive and supportive workplace culture.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: A review of your CV and portfolio to assess your qualifications, experience, and suitability for the role.

• Technical Interview (UI/UX & API): Expect questions and potentially a live coding or design exercise focusing on your UI/UX design process, frontend development skills (PHP, JavaScript), and API design/integration capabilities. This may involve discussing past projects and problem-solving scenarios.

• AI/Claude-Specific Discussion: A dedicated segment to gauge your understanding and practical experience with AI technologies, particularly Claude. Be ready to discuss how you've applied them or how you envision using them for Pakajo's platform.

• Cultural Fit & Behavioral Interview: Questions designed to understand your teamwork style, problem-solving approach, how you handle challenges, and how you align with Pakajo's values (innovation, teamwork, social responsibility).

• Final Interview: Potentially with a senior leader or hiring manager to discuss the role in more detail, your career aspirations, and finalize any offer details.

Portfolio Review Tips:

• Curate Strategically: Select projects that best highlight your UI/UX design skills, API development, and crucially, your AI integration experience (especially with Claude). Organize your portfolio logically.

• Tell a Story: For each project, clearly articulate the problem you solved, your role, the process you followed, the tools/technologies used, and the impact/results achieved. Quantify achievements where possible (e.g., "improved user engagement by X%", "reduced API response time by Y ms").

• Showcase Process: Include wireframes, user flows, prototypes, and design iterations to demonstrate your design thinking. For APIs, include diagrams or explanations of your architecture.

• Highlight AI Application: Clearly present how you've used AI (like Claude) to add value, whether it's enhancing user interaction, automating tasks, or providing intelligent insights.

• Be Ready to Discuss: Prepare to walk through your portfolio and answer in-depth questions about your design decisions, technical choices, and problem-solving strategies.

Challenge Preparation:

• Design Challenge: You might be given a task to design a specific feature or improve an existing one on the Pakajo platform, requiring you to demonstrate your UI/UX skills under timed conditions.

• API Design Task: Prepare to design a simple API endpoint based on a given scenario or review and critique an existing API design.

• Problem-Solving Scenarios: Be ready for hypothetical questions about optimizing user flows, handling API errors, or integrating new AI features. Focus on structured thinking and clear articulation of solutions.

📝 Enhancement Note: The interview process will likely be rigorous, testing both technical depth and practical application of specialized skills. A strong, well-prepared portfolio is non-negotiable for this role, especially showcasing AI integration.

🛠 Tools & Technology Stack

Primary Tools:

• UI/UX Design Tools: Figma, Sketch, Adobe XD, InVision (or similar for wireframing, prototyping, and visual design).

• Frontend Development: PHP, JavaScript, HTML5, CSS3. Experience with modern frameworks like React, Vue.js, or Angular is highly probable and beneficial.

• API Development: Understanding of RESTful principles, experience with API design tools (e.g., Swagger/OpenAPI), and potentially frameworks for API creation.

• AI & Machine Learning: Direct experience with Claude and other Large Language Models (LLMs). Familiarity with AI integration SDKs or APIs.

Analytics & Reporting:

• Web analytics tools for user behavior tracking (e.g., Google Analytics, Mixpanel, Amplitude).

• Performance monitoring tools for web applications and APIs.

• Tools for usability testing and feedback collection. CRM & Automation:

• While not explicitly mentioned for this role, understanding of how UI/UX and API integrations impact CRM systems (like Salesforce, HubSpot) or marketing automation platforms could be a plus.

• Familiarity with project management tools (e.g., Jira, Asana) for workflow tracking.

📝 Enhancement Note: The explicit mention of "PHP und Javascript" forms the core of the frontend stack. The critical differentiator is the "Claude" and "KI-gestützt" aspect, indicating a strong need for hands-on experience with AI models and their integration into web applications.

👥 Team Culture & Values

Operations Values:

• Innovation: A drive to continuously explore and implement new technologies and solutions, particularly in AI and user experience.

• Teamwork: Strong emphasis on collaboration, open communication, and mutual support within an international and cross-functional team.

• Social Responsibility: Commitment to ethical practices and contributing positively to the community and environment, as highlighted by the "award-winning employer" status.

• User-Centricity: A deep focus on understanding and meeting customer needs through intuitive design and effective functionality.

• Efficiency: Striving for optimized performance, streamlined processes, and effective solutions in both development and user interaction.

Collaboration Style:

• Cross-functional Integration: Expect to work closely with designers, product managers, backend developers, and marketing teams, requiring strong communication and coordination.

• Agile & Iterative: The team likely operates in an agile framework, valuing continuous feedback, quick iterations, and adaptability.

• Knowledge Sharing: A culture that encourages sharing best practices, learning from each other, and collectively solving complex problems.

📝 Enhancement Note: The company culture appears to be a blend of a dynamic startup environment with a focus on innovation and growth, balanced by established values of teamwork and social responsibility. This suggests a place where ambitious individuals can make a significant impact while being part of a supportive team.

⚡ Challenges & Growth Opportunities

Challenges:

• Rapid Technological Evolution: Staying current with the fast-paced advancements in UI/UX design, API technologies, and especially AI/LLMs like Claude requires continuous learning.

• Balancing Innovation and Stability: Integrating cutting-edge AI features while ensuring a stable, high-performing, and user-friendly platform can be complex.

• Cross-functional Alignment: Effectively translating diverse stakeholder needs (product, marketing, engineering) into cohesive UI/UX and API solutions.

• Scalability: Designing and developing systems that can handle significant growth in users and data volume as the company aims to become the largest portal.

Learning & Development Opportunities:

• AI Specialization: Deep dive into advanced AI concepts, prompt engineering, fine-tuning models, and exploring new AI tools beyond Claude.

• Advanced UI/UX: Master complex interaction design, accessibility standards, and performance optimization techniques.

• Full-Stack Acumen: Develop skills in backend languages, database management, or cloud infrastructure to gain a broader understanding of the tech stack.

• Industry Knowledge: Gain in-depth expertise in the eCommerce logistics sector, a high-growth area with significant technological demand.

• Mentorship & Leadership: Opportunities to mentor junior developers and potentially step into leadership roles as the team expands.

📝 Enhancement Note: The challenges presented are typical for a role at the forefront of technology. Pakajo's commitment to professional development suggests that employees will be supported in overcoming these challenges and capitalizing on growth opportunities.

💡 Interview Preparation

Strategy Questions:

• UI/UX Strategy: "Describe your process for designing a complex user interface from scratch. How do you incorporate user feedback and iterate on designs?"

• API Design & Integration: "Walk me through a challenging API integration you've worked on. What were the technical hurdles, and how did you overcome them?"

• AI Application: "How would you leverage Claude or similar LLMs to enhance the user experience of an eCommerce shipping comparison portal? Provide specific feature ideas."

• Problem-Solving: "Imagine our portal experiences a significant drop in user engagement. What steps would you take to diagnose the issue from a UI/UX and API perspective?"

Company & Culture Questions:

• "What interests you most about Pakajo GmbH and our mission to revolutionize eCommerce shipping?"

• "How do you contribute to a collaborative and innovative team environment?"

• "How do you stay updated on the latest trends in UI/UX, API development, and AI?" Portfolio Presentation Strategy:

• Structure Your Narrative: Start with an overview of your most relevant projects, then dive into 1-2 detailed case studies.

• Focus on Impact: Clearly articulate the business value and user benefits of your work, using data and metrics whenever possible.

• Explain Your 'Why': Be ready to justify your design decisions, technical choices, and API architectures.

• Demonstrate AI Fluency: Show, don't just tell, how you've applied AI. Be prepared for live demonstrations or detailed explanations of AI-driven features.

• Engage with Questions: Treat the portfolio review as a collaborative discussion. Be open to feedback and further exploration of your work.

📝 Enhancement Note: Candidates should prepare to discuss their experience with specific technologies mentioned (PHP, JavaScript, Claude) and demonstrate how they can apply their skills to Pakajo's unique challenges in the eCommerce logistics space. The ability to articulate AI integration strategies will be key.

📌 Application Steps

To apply for this UI/UX & API Developer position:

• Submit your application through the provided link on join.com.

• Customize Your Resume: Tailor your resume to highlight your experience with UI/UX design, API development, PHP, JavaScript, and specifically any work with AI or LLMs like Claude. Use keywords from the job description.

• Prepare Your Portfolio: Ensure your portfolio is up-to-date, well-organized, and prominently features projects demonstrating your UI/UX design process, API integration experience, and practical application of AI technologies.

• Research Pakajo GmbH: Understand their mission, values, and the competitive landscape of eCommerce shipping. Familiarize yourself with their existing platform if possible.

• Practice Interview Questions: Prepare to answer technical, behavioral, and AI-specific questions, and be ready to present your portfolio and discuss your past projects in detail.

⚠️ 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.

---