(Senior) Product Designer - Heartbeat App (m/f/d)

📍 Job Overview

Job Title: Senior Product Designer - Heartbeat App (m/f/d) Company: 1KOMMA5˚ Location: Berlin, Germany Job Type: CONTRACTOR Category: Product Design / UX/UI Design Date Posted: September 10, 2025 Experience Level: Mid-Senior Level (4+ years) Remote Status: Hybrid

🚀 Role Summary

• Spearhead the design of user-centric digital products within the Heartbeat App team, focusing on energy consumption and production data visualization.
• Translate complex energy models and AI decisions into intuitive, simple, and visually appealing user interfaces.
• Drive the end-to-end product design process, from problem definition and discovery to rapid high-fidelity design creation and iterative improvements.
• Collaborate closely with product managers, designers, and developers in an agile setting to deliver exceptional user experiences that align with business objectives.

📝 Enhancement Note: This role is a 12-month fixed contract with potential for extension, indicating a need for immediate impact and a strong ability to integrate quickly into existing project workflows. The focus on "Heartbeat AI decisions" and "price curves" suggests a data-intensive and potentially complex domain requiring strong analytical and visualization design skills.

📈 Primary Responsibilities

• Lead the design of new and existing features for the Heartbeat App, focusing on clarity of energy consumption/production data, Heartbeat AI decisions, price curves, and live system statuses.
• Autonomously create high-fidelity, interactive prototypes and designs that significantly enhance the overall user experience.
• Iteratively refine design solutions based on feedback from users, stakeholders, and data-driven insights, ensuring continuous improvement.
• Collaborate with cross-functional teams, including product managers and engineers, to define user problems, conduct design research, and translate requirements into design specifications.
• Advocate for user-centered design principles and best practices, contributing to the evolution of the company's design language and UX patterns.
• Actively participate in the agile development process, contributing to sprint planning, backlog refinement, and design reviews.

📝 Enhancement Note: The emphasis on "autonomously creating high-fidelity interactive designs" and "rapidly create high fidelity designs" suggests a need for a designer who can work independently and produce polished deliverables efficiently. The requirement to "quickly understanding complex models & problems, and designing them into intuitive, simple, user-centric solutions" highlights the importance of strong analytical thinking and the ability to simplify complex information for end-users.

🎓 Skills & Qualifications

Education: While no specific degree is mandated, a Bachelor's or Master's degree in Design, Human-Computer Interaction, or a related field is often implied for senior-level roles. Experience: Minimum of 4 years of professional experience in mobile app product design, with a proven track record of building user-centric digital products. Experience in a fast-paced scale-up environment is highly valued.

Required Skills:

• Minimum 4 years of mobile app product design experience.
• Proven expertise in user-centric design principles and methodologies.
• Strong proficiency in visual design, including layout, typography, color theory, and iconography.
• Demonstrated ability in data visualization design, translating complex data sets into understandable and actionable insights.
• Solid understanding of accessibility standards and best practices (WCAG).
• Experience working within an Agile development framework.
• Proficiency in industry-standard design and prototyping tools (e.g., Figma, Sketch, Adobe Creative Suite).
• Excellent written and spoken English communication skills.
• Ability to collaborate effectively with cross-functional teams.

Preferred Skills:

• Experience or demonstrable knowledge within the climate tech industry.
• Fluency in German (written and spoken).
• Experience designing for complex data dashboards or energy management applications.
• Familiarity with user research methodologies and usability testing.

📝 Enhancement Note: The requirement for strong English skills and German fluency as a bonus indicates the primary working language is English, but a German-speaking environment is present. The "climate tech industry" preference suggests that an understanding of the company's mission and domain is beneficial for design impact.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• A curated portfolio showcasing a minimum of 4 years of impactful mobile app product design work, demonstrating a clear progression from problem identification to solution implementation.
• Case studies that highlight your ability to tackle complex problems, particularly those involving data visualization and the simplification of intricate information.
• Demonstrations of your process for user research, ideation, wireframing, prototyping, and final visual design, with clear explanations of your decision-making rationale.
• Evidence of iterative design improvements driven by user feedback, stakeholder input, and data analysis.
• Examples of collaboration with engineering and product management teams, showcasing your ability to work effectively in cross-functional environments.

Process Documentation:

• Showcase your approach to defining user problems, conducting discovery phases, and rapidly iterating on high-fidelity designs.
• Illustrate your methods for translating complex models and data into intuitive, user-centric solutions.
• Provide examples of how you contribute to and improve design languages and UX patterns within a team.

📝 Enhancement Note: Given the role's focus on complex data visualization and AI decisions, portfolios should strongly emphasize projects where the candidate successfully simplified complex information, improved data comprehension, and demonstrated measurable user experience enhancements through design.

💵 Compensation & Benefits

Salary Range: For a Senior Product Designer with 4+ years of experience in Berlin, Germany, a competitive salary range would typically fall between €60,000 and €85,000 annually. As this is a contract position, the rate would likely be structured hourly or daily, potentially aligning with a higher annual equivalent to account for the fixed-term nature and lack of long-term employment benefits.

Benefits:

• Dynamic Team Environment: Opportunity to work with driven individuals committed to making a significant positive impact.
• Flat Hierarchies & Short Decision Paths: Facilitates quick learning, direct involvement, and agility in project execution.
• Welcoming and Familiar Team: Emphasis on a supportive and friendly team culture.
• Purpose-Driven Work: Contribution to the energy transition, offering a sense of meaningful impact.
• Office Locations: Flexibility to work from offices in Hamburg, Berlin, or Munich.
• EGYM Wellpass: Access to a wide range of fitness and wellness facilities.
• Futurebens: Benefits and discounts program.
• Job Bike Leasing: Option for company-sponsored bicycle leasing, promoting health and environmental consciousness.

Working Hours: The stated working hours are 40 hours per week, typical for a full-time role, which will likely be the basis for the contract duration.

📝 Enhancement Note: The salary estimate is based on industry benchmarks for senior product designers in major German cities, adjusted for the contract nature of the role. The benefits listed are standard for German employment and reflect a company culture that values employee well-being and engagement.

🎯 Team & Company Context

🏢 Company Culture

Industry: Renewable Energy / Climate Tech / Smart Home Technology. 1KOMMA5˚ is positioned at the intersection of these growing sectors, aiming to be a comprehensive provider of energy solutions. Company Size: While not explicitly stated in the provided data, the mention of multiple office locations (Berlin, Munich, Hamburg) and a growing tech team suggests a company that has moved beyond startup phase and is in a significant growth or scale-up phase, likely employing several hundred to over a thousand people. Founded: The founding date is not provided, but the company's mission implies a relatively recent establishment focused on the current energy transition landscape.

Team Structure:

• The role is within the "Heartbeat App team," suggesting a specialized product team focused on a core software offering. This team likely includes Product Managers, fellow Designers, and Software Engineers.
• Reporting structure is not detailed, but "flat hierarchies and short decision-making paths" imply a less bureaucratic organization where direct communication with stakeholders is common.
• Cross-functional collaboration is a key aspect, as the designer will work closely with product managers and developers.

Methodology:

• The company operates in an agile environment, emphasizing iterative development and rapid feedback loops.
• Design processes will likely involve user research, rapid prototyping, usability testing, and data analysis to inform design decisions.
• A focus on "mission-focused designers" suggests an environment where mission alignment and impact are valued alongside design quality.

Company Website: http://1komma5grad.com

📝 Enhancement Note: The company's focus on the energy transition and its "one-stop-shop" model for solar, heat pumps, and charging infrastructure indicates a mission-driven culture. For a designer, this means understanding the user's journey in adopting and managing these technologies, which can be complex.

📈 Career & Growth Analysis

Operations Career Level: This is a Senior Product Designer role, indicating a significant level of autonomy and responsibility. It's a position where you are expected to lead design initiatives, mentor junior designers (if any), and influence product strategy through your design expertise. Reporting Structure: The designer will likely report to a Head of Product, Design Lead, or a Senior Product Manager within the Heartbeat App team. Collaboration will be broad, extending to engineers and other product teams. Operations Impact: The designer's work directly impacts user adoption and satisfaction with the Heartbeat App, which is a key digital touchpoint for 1KOMMA5˚ customers. Successful UX/UI design can drive higher engagement with energy management features, improve customer understanding of their energy usage, and ultimately support the company's mission and revenue goals by enhancing the overall customer experience.

Growth Opportunities:

• Specialization: Opportunity to deepen expertise in data visualization and designing for complex technical products within the renewable energy sector.
• Leadership: Potential to lead design projects, mentor junior team members, and influence design strategy as the company scales.
• Cross-functional Exposure: Gain experience working across different aspects of the energy tech value chain, from hardware integration to software services.
• Contract Extension/Full-Time Conversion: Based on performance and business needs, there may be opportunities for continued engagement or transition to a permanent role.

📝 Enhancement Note: The "Senior" title coupled with a contract role suggests that the company is looking for someone who can hit the ground running and immediately contribute at a high level, possibly to address specific project needs or to augment the team's existing capabilities. Growth would likely come from taking on more complex projects or leadership responsibilities within the design function.

🌐 Work Environment

Office Type: The company offers work from offices in Hamburg, Berlin, or Munich, suggesting modern, collaborative office spaces designed to foster teamwork and innovation. Office Location(s): Berlin, Hamburg, Munich – major tech hubs in Germany, offering good connectivity and access to talent.

Workspace Context:

• Expect a dynamic environment with a mix of focused work and collaborative sessions, typical of agile tech teams.
• Access to standard design software and hardware will be provided. The emphasis on "flat hierarchies" and "short decision paths" implies an open and communicative workspace.
• Opportunities for interaction with a diverse team of professionals passionate about the energy transition.

Work Schedule: The standard working hours are 40 hours per week. While contract roles can sometimes offer more flexibility, the expectation is likely adherence to a structured work week, with potential for flexibility depending on team needs and project deadlines.

📝 Enhancement Note: The choice of major German cities for office locations provides a good working environment with access to amenities and a strong professional network. The hybrid nature of the role means a balance between in-office collaboration and remote work, requiring self-discipline and effective communication for both settings.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: A review of your resume and portfolio to assess relevant experience and design skills. Be prepared to briefly walk through your most relevant projects.
• Hiring Manager/Team Interview: A discussion about your experience, design philosophy, and how you approach problem-solving. Expect questions about your collaboration style and experience in agile environments.
• Design Challenge/Portfolio Deep Dive: This may involve presenting specific case studies from your portfolio, focusing on your process, decision-making, and the impact of your designs. A practical design exercise related to data visualization or simplifying complex information might also be included.
• Cross-functional Team Interviews: Meetings with product managers and/or engineers to assess your collaboration and communication skills within a team context.
• Final Interview: Potentially with a senior leader to discuss cultural fit and strategic alignment.

Portfolio Review Tips:

• Curate Strategically: Select 2-3 projects that best showcase your skills in mobile app design, data visualization, and simplifying complex information. Tailor your selection to the requirements of this role.
• Tell a Story: For each project, clearly articulate the problem, your role, the design process, key decisions, challenges faced, and the measurable outcomes or impact of your design. Use visuals effectively.
• Highlight Process: Show your thinking process – sketches, wireframes, user flows, prototypes, and user testing insights. Demonstrate how you iterate based on feedback.
• Quantify Impact: Wherever possible, use metrics to demonstrate the success of your designs (e.g., improved user engagement, reduced task completion time, increased data comprehension).
• Prepare for Questions: Be ready to answer questions about your design choices, how you handle design disagreements, and how you adapt to feedback.

Challenge Preparation:

• Understand the Domain: Familiarize yourself with the climate tech industry and the challenges of visualizing energy data. Research competitors or similar apps.
• Practice Data Visualization: Be prepared to discuss or demonstrate how you would approach visualizing energy consumption, production, and AI-driven insights.
• Simplify Complexity: Think about how you would break down complex technical information into easily digestible user interfaces.
• Agile Context: Consider how your design process integrates with agile sprints and how you communicate design progress and blockers.

📝 Enhancement Note: The emphasis on "complex models" and "data visualization" means your portfolio and any design challenge should explicitly demonstrate your ability to handle intricate information and make it accessible. Be ready to discuss your process for user research and validation, as this is crucial for designing user-centric solutions in a technical domain.

🛠 Tools & Technology Stack

Primary Tools:

• Design & Prototyping: Figma (highly likely, as it's the industry standard), Sketch, Adobe XD, InVision.
• Collaboration: Slack, Jira, Confluence (common in agile environments for team communication and project management).

Analytics & Reporting:

• Analytics Platforms: Google Analytics, Amplitude, Mixpanel (for understanding user behavior within the app).
• Data Visualization Tools: Tableau, Power BI, or custom-built dashboards (for analyzing app usage data and potentially for designing how data is presented within the app itself).

CRM & Automation:

• CRM: Salesforce, HubSpot (less likely for a direct designer role, but awareness is good).
• Integration/Workflow Tools: Zapier, Make (Integromat) (for understanding how different systems connect, though not typically a designer responsibility).

📝 Enhancement Note: Proficiency in Figma is almost certainly a prerequisite given its prevalence. Experience with tools that facilitate user research, usability testing, and A/B testing will also be highly beneficial. Understanding the data that flows into and out of the app will be key to designing effective visualizations.

👥 Team Culture & Values

Operations Values:

• Mission-Driven Impact: A strong commitment to the company's mission of advancing the energy transition. Designers are expected to contribute to this mission through their work.
• Data-Driven Decisions: Emphasis on using data and user insights to inform design choices and measure success.
• Agility & Speed: Operating in a fast-paced environment requires adaptability, quick iteration, and the ability to deliver results efficiently.
• Collaboration & Transparency: Open communication, shared learning, and a willingness to provide and receive constructive feedback are highly valued.
• User-Centricity: A core value of placing the user at the center of all design decisions.

Collaboration Style:

• Cross-functional Integration: Designers work closely with Product Managers to define requirements and scope, and with Engineers to ensure feasibility and successful implementation of designs.
• Iterative Design Feedback: A culture of continuous feedback on designs, both within the design team and from product and engineering.
• Knowledge Sharing: Encouragement to share learnings, best practices, and design challenges to foster collective growth and efficiency.

📝 Enhancement Note: The company's focus on "making things happen" and "moving companies forward" suggests a proactive and results-oriented culture. For a designer, this means being comfortable proposing solutions, driving initiatives, and demonstrating the value of design through tangible outcomes.

⚡ Challenges & Growth Opportunities

Challenges:

• Simplifying Complex Data: The primary challenge will be translating intricate energy consumption data, AI algorithms, and pricing models into easily understandable and actionable interfaces for users who may not be technical experts.
• Balancing User Needs with Technical Constraints: Ensuring designs are user-friendly while also being technically feasible within the Heartbeat App's architecture and data capabilities.
• Fast-Paced Environment: Adapting to the rapid iteration cycles common in scale-up environments, requiring quick decision-making and efficient design output.
• Contractual Nature: Adapting to a fixed-term contract, which requires a focus on delivering high-impact results within a defined timeframe.

Learning & Development Opportunities:

• Domain Expertise: Gaining deep knowledge of the renewable energy sector, smart home technology, and energy management systems.
• Advanced Data Visualization: Honing skills in designing effective and engaging data visualizations for complex datasets.
• Product Strategy Influence: Opportunities to contribute to product strategy discussions and influence the direction of the Heartbeat App.
• Exposure to AI in Design: Working with AI-driven features provides insights into how AI impacts user experience design.

📝 Enhancement Note: The challenges presented are typical for roles involving complex technical products. Success will depend on strong analytical skills, excellent communication, and a proactive approach to problem-solving. The growth opportunities are significant for a designer looking to specialize in a rapidly growing and impactful industry.

💡 Interview Preparation

Strategy Questions:

• "Describe a time you designed a product or feature that simplified a complex technical concept for end-users. What was your process, and what was the outcome?" (Focus on data visualization, user research, iteration, and impact).
• "How do you approach collaborating with product managers and engineers in an agile environment to ensure design feasibility and timely delivery?" (Highlight communication, feedback loops, and understanding of agile workflows).
• "Walk us through a project from your portfolio that best demonstrates your ability to design for mobile apps with a strong focus on data visualization." (Be ready to present your case study, detailing your design decisions and their rationale).
• "What are your thoughts on designing for the climate tech industry? How do you ensure user adoption of new energy technologies through design?" (Showcase your understanding of the domain and user motivation).
• "How do you stay updated on design trends and incorporate them into your work while maintaining a user-centric approach?" (Demonstrate continuous learning and a balanced perspective).

Company & Culture Questions:

• "What interests you about 1KOMMA5˚ and our mission to drive the energy transition?" (Research the company's mission, values, and recent news).
• "How do you contribute to a positive and collaborative team environment?" (Share examples of your teamwork and communication style).
• "Based on your understanding, what do you see as the key design challenges for the Heartbeat App?" (Demonstrate you've thought critically about the role and product).

Portfolio Presentation Strategy:

• Structure: For each case study, use a clear narrative: Problem -> Your Role -> Process -> Solution -> Results/Impact.
• Visuals: Use high-quality mockups, prototypes, user flows, and potentially user testimonials or data points.
• Conciseness: Be prepared to present your key projects within a limited timeframe (e.g., 15-20 minutes), allowing ample time for Q&A.
• Engagement: Be enthusiastic, articulate your thought process clearly, and be ready to defend your design decisions and discuss alternatives considered.

📝 Enhancement Note: Expect interviewers to probe deeply into your process, especially how you handle ambiguity and complexity. They will be looking for evidence of your ability to translate user needs and technical requirements into elegant and effective design solutions, particularly in the realm of data.

📌 Application Steps

To apply for this operations position:

• Submit your application through the provided link on join.com.
• Portfolio Customization: Ensure your portfolio is easily accessible (link provided on resume/application) and clearly highlights your most relevant mobile app design projects, with a strong emphasis on data visualization and complex problem-solving.
• Resume Optimization: Tailor your resume to emphasize your 4+ years of mobile product design experience, specific achievements in UX/UI, data visualization, and agile environments. Quantify your impact whenever possible.
• Interview Preparation: Practice articulating your design process, defending your design decisions, and discussing your experience with data and complex systems. Prepare to present 2-3 key portfolio case studies.
• Company Research: Thoroughly research 1KOMMA5˚'s mission, products, and values. Understand their role in the energy transition and how the Heartbeat App fits into their ecosystem.

⚠️ 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.