Senior Product Designer- Hardware

Senior Product Designer
- Hardware (fixed term 12 months)
Berlin, Germany
· Product & Design

Hardware is the team behind the card readers merchants use every day to take payments, from a market stall to a busy café till. The role sits within the Solo squad, working across embedded systems, on-device UI, companion app, and backend, so decisions made here shape a product experience unlike a typical app role. Whoever joins will step into a well-established craft with real scope to shape how the next generation of Solo evolves, working directly with engineering to bring ideas from concept to something millions of merchants use daily.

Own product design end to end for Solo: framing problems, running research, defining UX flows and information architecture, and delivering production-ready designs

Work across the full hardware experience (embedded, on-device UI, app, and backend), partnering with product management and engineering to reach the best solution for merchants

Make and explain design trade-offs against real technical constraints, without compromising product quality

Partner with product to define success metrics tied to business goals, and use data to validate design decisions

Evolve Sum Up's global design system (Circuit UI) and the Solo hardware UI library, keeping a consistent design vision

Share feedback and craft knowledge with the wider design chapter

Extensive experience owning complex product design work independently, with deep expertise in either UX or UI and strong skills in the other

Comfort defining multi step flows and information architecture, accounting for edge cases and dependencies across the user journey

Fluency with common design and prototyping tools, particularly Figma

A human centred design process, backed by both qualitative and quantitative research methods

Ability to translate technical constraints into design trade-offs and document them clearly in specs

Track record shipping complex products through a full development cycle in an agile environment

Nice to have:

Experience with hardware, smart devices, or IoT products

Experience launching products in new or global markets, including localisation and multi screen considerations

• Opportunity to work with Sum Uppers globally on large-scale fintech products used by millions of businesses worldwide, from our Berlin office. This involves an office-first setup
• Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced
• Enrolment onto our Virtual Stock Option programme: you will own a stake in Sum Up's future success
• A dedicated annual L&D budget of €2000 for your individual development, which can be used to attend conferences and/or advance your career through further education
• A corporate pension scheme where we match up to 20% of your contributions
• Generous time off: enjoy 28 days of paid leave plus public holidays and special leave days
• Numerous other benefits such as Urban Sports Club subsidy, Kita placement assistance, subsidised office lunches
• Break4me: 1-month sabbatical after 3 years of service
• Referral Bonus: earn additional rewards by referring talented individuals to join the Sum Up team

Be empowered to do more that matters.

At Sum Up, we're on a mission to empower small businesses across the globe by providing simple and affordable tools that allow them to thrive. Today, over 4 million businesses in 38 markets rely on Sum Up as their financial partner to manage payments, finance and customer relationships.

Our commitment to small businesses is reflected in our diverse team Opens in new window of over 3,000 Sum Uppers from over 90 nationalities, united by global collaboration and an innovative mindset. Our core values lay the foundation for who we are and what we stand for, shaping our work culture and driving our success. We foster inclusivity and a continuous learning culture, providing a safe space for personal and professional growth.

Our differences make us unique and strong as we strive to create an environment where everyone belongs and feels supported, no matter how they identify.

Sum Up is proud to be an Equal Employment Opportunity employer, actively seeking and embracing diversity in our workforce. We don't make hiring or employment decisions based on race, colour, religion or religious belief, ethnic or national origin, nationality, sex, gender, gender identity, sexual orientation, disability, age or any other basis protected by applicable laws or prohibited by company policy. Our commitment extends beyond recruitment to creating a safe and respectful workplace where harassment of any form is strictly prohibited.

Discover more about our culture and opportunities on our careers website , and follow our journey on Linked In Opens in new window , Instagram Opens in new window , and Tik Tok Opens in new window .