SumUp UX/UI Designer interview questions & guide 2026

The following questions are representative of the patterns reported by candidates. Use them to reflect on your own design practice and your ability to articulate the "why" behind your work.

Design Process and Methodology

These questions test your ability to structure your work and explain your problem-solving framework.

• Describe your design process.
• How do you conduct user research?

Preparation at SumUp should focus on your ability to connect your design decisions to business value. You are not just a pixel-pusher; you are a product partner.

Role-Related Knowledge – You must be able to articulate your design methodology clearly. Be prepared to discuss how you bridge the gap between user research and UI implementation, ensuring your solutions are both usable and feasible.

Problem-Solving Ability – Interviewers will look at how you deconstruct ambiguous problems. Focus on your ability to define the problem space, iterate based on feedback, and measure success through user data or business metrics.

Ownership and Leadership – At SumUp, you are expected to take initiative. Demonstrate this by sharing stories where you identified a problem, took responsibility for the solution, and mobilized your team to deliver results.

Culture Fit and Communication – The team values transparency, collaboration, and a global perspective. Show that you can work effectively across disciplines, including non-design stakeholders like legal or engineering, to achieve a common goal.

The hiring process at SumUp is designed to be comprehensive, often involving multiple touchpoints to ensure that the team understands your technical depth and your cultural alignment. While the structure can vary by seniority and location, you should expect a sequence that transitions from high-level screenings to deep-dive technical and behavioral evaluations.

You will likely interact with a mix of recruiters, design managers, product leads, and occasionally stakeholders from outside the core design function. This multi-disciplinary approach allows SumUp to assess not just your craft, but your ability to communicate complex design concepts to non-designers. Be prepared for a process that emphasizes portfolio reviews and, in many cases, a design challenge or task to assess your real-world problem-solving skills.

The timeline above represents a typical progression, though it can fluctuate based on the specific team's needs. Use this to pace your preparation—prioritize your portfolio narrative for early rounds and reserve your energy for the technical deep-dives and cultural assessments that occur later in the process.

Portfolio and Craft

Your portfolio is the primary window into your professional capabilities. Interviewers look for clear storytelling—how you identified a problem, the research you conducted, and why you chose specific design paths.

Be ready to go over:

• The "Why" – Don't just show the final UI; explain the decisions that led there.
• Collaboration – How you interacted with developers and product managers during the build.
• Failure and Iteration – A project that didn't go as planned and what you learned.

Behavioral and Cultural Alignment

SumUp looks for "ownership" and a proactive attitude. They want designers who are not just waiting for instructions but are actively looking for ways to improve the product.

Be ready to go over:

• Ownership Mindset – Examples of when you went beyond your job description to ensure a project's success.
• Cross-Functional Empathy – How you navigate disagreements with engineering or stakeholders.
• Adaptability – How you handle shifting priorities in a fast-moving fintech environment.

As a UX/UI Designer, your day-to-day will revolve around creating solutions that simplify financial transactions for merchants. You will be responsible for creating user flows, wireframes, and high-fidelity prototypes that adhere to SumUp's design system.

Beyond the screen, you will participate in regular design critiques, conduct user testing sessions, and synthesize feedback into actionable iterations. You are expected to be a bridge between the user’s needs and the technical constraints of the platform. You will work in a squad-based structure, meaning you will have daily contact with engineers to ensure that what you design is technically feasible and implemented with high quality.

A competitive candidate for this role demonstrates a strong balance of hard design skills and soft interpersonal skills.

• Must-have skills:
  • Proficiency in modern design tools (e.g., Figma, Sketch).
  • A strong portfolio demonstrating end-to-end product design experience.
  • Ability to articulate design decisions based on data or user research.
  • Fluency in English, as SumUp operates in a global, multi-cultural environment.
• Nice-to-have skills:
  • Experience in fintech or complex transactional systems.
  • Familiarity with hardware-software integration design.
  • Experience working in Agile or Scrum environments.

Q: How much time should I spend preparing for the design challenge? A: Treat the design challenge as a demonstration of your thought process rather than a race to perfection. Focus on clearly defining the problem and justifying your design choices.

Q: Is the culture at SumUp highly collaborative? A: Yes, the environment is very social and collaborative. You will be expected to work closely with cross-functional partners, so your ability to communicate and build relationships is just as important as your UI skills.

Q: What is the typical interview-to-offer timeline? A: While it can vary, the process is often thorough and may span several weeks to ensure a good fit. Be patient, but do not hesitate to ask for clear timelines from your recruiter.

Q: Does SumUp value remote or hybrid work? A: Most design roles are based in hubs like Berlin or São Paulo. Check the specific job posting for the most current information regarding location and office attendance expectations.

• Prioritize the "Why": Never show a screen without explaining the user problem it solves.
• Be Ready for Peer Reviews: You will likely be interviewed by other designers; be humble, open to critique, and show that you value team feedback.
• Prepare for Non-Designers: Practice explaining your design decisions in simple, business-focused terms for product managers or legal stakeholders.

The UX/UI Designer role at SumUp is a unique opportunity to shape the financial tools used by small business owners globally. By focusing on your ability to articulate your design process, demonstrate an ownership mindset, and show empathy for both the user and your cross-functional teammates, you will position yourself as a strong candidate.

Candidates can explore additional interview insights, practice questions, and preparation resources on Dataford. Remember that thorough, structured preparation is your best tool for success. Approach your interviews with confidence, be ready to tell your story, and focus on the impact you can bring to the team.

The module above provides insights into compensation trends for this role. Use this data to understand the market range and ensure your expectations align with the seniority and responsibilities of the position.