Senior Product Designer (m/w/d)

Your Mission

We are looking for a Senior Product Designer to help shape Ostrom’s next generation of consumer energy products. You will work across mobile app experiences, smart device integrations, tariffs, growth, and retention, translating complex energy logic into simple, trustworthy, and useful customer journeys.

You will be part of the core Product team and work closely with Product Managers, Engineering, Marketing, and Operations. Beyond designing individual features, you will help mature our design practice, mentor another product designer and play a crucial role in defining, prioritizing, and delivering quality experiences that align with our overall mission of build Europe’s leading energy management platform to provide fair, clean energy to everyone.

What you will be keeping busy with

• Design Ownership: Own the end-to-end product design process, from problem and solution discovery (in tandem with your Product Manager), to wireframing and prototyping, to producing impact-driving and delightful designs that are ready to be delivered by engineers, to defining success criteria and monitoring after launch.
• Complex UX Simplification: Translate complex energy products such as tariffs, smart devices, automation, and optimisation into simple, trustworthy customer experiences.
• Collaboration & Stakeholder Management: Collaborate closely with Product Managers, the tech team, and stakeholders to define requirements, facilitate workshops, iterate on solutions, and deliver designs that align with business & customer goals, and that balance design quality and timely delivery.
• Strategy & Roadmap Development: Support product managers and relevant stakeholders to develop and maintain a prioritised product roadmap that maintains a high bar for design and user experience, ensuring continual alignment with business objectives.
• Design Leadership & Processes: Maintain and elevate ongoing design processes and artefacts such as design systems, tooling, standards and trends, collaboration methods, educating and mentoring others in the product and tech teams on best practices.
• Mentoring & Design Practice: Mentor and support another product designer, provide thoughtful feedback, and help establish pragmatic design rituals, standards, and ways of working.
• Customer & Design Advocacy: Use user research, product metrics, usability testing, support feedback, and design expertise to become an internal expert and advocate on how customers think, what a good user experience means for them, and how we should reflect that in our product.

Your profile:

• 4+ years of experience as a Product Designer, with clear ownership of complex mobile or web product experiences in ideally a fast-paced and dynamic startup/tech company.
• User-centric and naturally curious, knowing how to do user research, usability testing, and hypotheses validation, constantly wondering why users do what they do, with strong instincts on what makes a good user experience to delight customers.
• Strong understanding of UX principles, visual design, and interaction design, and loves to be on top of the latest market trends.
• Strong UI judgment: Design patterns, hierarchy, spacing, typography, accessibility, and overall interaction quality.
• Experience contributing to and improving design systems that ensure products are cohesive and consistent.
• Pragmatic and flexible, knowing when to accept 'good enough’ vs challenging the status quo. We pride ourselves on moving quickly but with confidence.
• Strong ability to simplify complex product logic, data, settings, and system states into clear user experiences.
• Strong ownership with excellent problem-solving skills, organisational skills, and attention to detail with experience working in an agile environments while collaborating with cross-functional teams.
• Great stakeholder management skills, including communication, alignment, and gathering and integrating feedback. We like to promote a culture of transparency.
• Strong command of English. We are a vibrant international team with English being our company-wide language.