Sileon FinTech

Cloud-Based
BNPL SaaS

Case Study

Building a SaaS platform from the ground up. An overview of the end-to-end journey.

Contents

1. Introduction
2. Mission & Challenges
3. Product Design Process
4. Design System & Organization
5. Wrap Up & Handover

1. Introduction

Sileon: A New Era for Paynova

After more than 20 years providing digital payment solutions in the Nordics, Swedish fintech Paynova found itself at a crossroads, pivoting from a consumer-facing solution to a cloud-based SaaS model, targeting banks, card issuers, and fintechs.

This transformation was reinforced by a strategic partnership with Visa, prompting a full-scale rebrand and internal restructuring. Leadership was renewed across Product, Tech, Marketing, and Sales, ultimately culminating in the formation of a new company, Sileon.

This case study reflects on my journey as Sileon’s founding product designer, covering the process and challenges of developing a cloud-based SaaS platform (MVP) from inception to its release, including the planning and implementation of a new design system and laying the foundation for a growing design team and organization.

Note: Paynova continued operating as a brand under Sileon’s umbrella until its eventual acquisition in 2024 by Swedish payment solutions provider Avarda.

2. Mission & Challenges

From Competitor to Partner

Paynova’s overarching goal was to shift from offering a BNPL solution targeted at end-consumers—where it had been competing in the Nordic market against giants like Klarna as a creditor itself—to a SaaS model. This new direction aimed to leverage Paynova’s expertise and technology to empower banks, card issuers, and fintechs to build and launch their own BNPL offering.

As part of this transformation, we were tasked with the mission of transforming the technology behind Paynova’s consumer-facing solutions into a flexible suite of cloud-based services, covering the entire BNPL journey. The result would be delivered as a seamless, API-based plug-and-play solution, configurable through a user-friendly UI.

Transforming Complex Legacy Systems into a Modern and Intuitive SaaS Platform

The new platform was to be developed on top of Paynova’s core systems, which had been developed over the years to be operated in-house and designed for internal use only, requiring specialized technical knowledge to configure.

This posed significant challenges, mainly due to technical restrictions and the inherent complexity of the configuration flows, which, despite offering a high degree of flexibility, were never designed with usability in mind.

Domains

Sileon70%Paynova20%Marketing10%

Balancing Multiple Roles in a Fast-Paced Environment

At Sileon, I was tasked with leading the design strategy and process from day one. As the only in-house designer at the time, I had to balance my responsibilities efficiently, continuing to support Paynova while gradually shifting my focus to the new business domain, until a new designer could take over the Paynova side.

In parallel, I had to step in to cover product management duties to keep Paynova’s roadmap on track during a period of team restructuring, while also contributing to product marketing when needed.

3. Product Design Process

Figma project containing the fully interactive prototype of the Sileon Portal—the main user interface for Sileon’s SaaS solution. For this project, I chose to keep the entire platform within a single page to promote transparency and provide all teams with a holistic view—serving as a unified source of truth.

Dealing With Uncertainty

Beyond the idea of transitioning towards a cloud-based SaaS model, not much had been decided or defined yet, which—together with the aforementioned temporary leadership void at Sileon, particularly in key areas like Product and Tech—had left us without clear direction and tangible goals to begin with.

This led to endless, unproductive meetings and an overall sense of chaos during the first few weeks. In an attempt to support the team, I stepped up and began organizing workshops as a facilitator, leveraging my previous experience with startups working on early-stage products. Working closely with the interim CPO and PM’s, we gradually began to move things forward, paving the way for a more structured approach.

Leap-of-Faith Assumptions

At first, the only tangible outcome we could produce was a list of assumptions—some of them critically important, such as “We believe there is demand for third-party BNPL solutions among banks”, which was fundamental to the decision to pivot to a BNPL SaaS model.

We all recognized the need to gain deeper insights before proceeding, as there were still many unanswered questions. By openly formulating assumptions around these uncertainties, we created a foundation for taking action and systematically validating our hypotheses.

User-Centered Design

After gaining clarity on the direction to take, we formed the first two development teams and began ideating different solutions. As the sole designer, I led the design strategy for both teams while also facilitating discovery sessions with the interim CPO, focusing on the development of additional solutions within our SaaS platform.

Being involved from the start and across multiple teams simultaneously gave me a broad view of the overall process and allowed me to establish best practices and a user-centric approach early on. This foundation helped us define user personas and map their journeys holistically, enabling a cohesive experience across all product areas.

Validating Information Architecture

After defining the user needs and goals, and once we had a clear understanding of the content and functionality our product would offer, we proceeded to map the information architecture (IA) for the entire platform, ensuring all teams were aligned.

It provided both teams with a clear blueprint for how information and functionality would be organized throughout the portal, facilitating business and technical discussions, and enabling quick iteration of the model before proceeding with the creation of the first prototypes.

Low-Fidelity Prototyping

At the time we began prototyping, neither a name nor a brand identity had been defined. Sileon hadn’t been established yet, as the branding was still being developed in parallel by the marketing team in collaboration with an external agency. Meanwhile, the design system was in its early stages, as I had only just begun planning it.

Once the information architecture was validated—serving as a foundational wireframe—we moved forward with the first low-fidelity prototypes. Having a tangible representation of the solution for the first time streamlined collaboration across teams, accelerated decision-making, and laid the foundation for defining the MVP scope.

High-Fidelity Prototyping

With a new CPO joining the team and the brand identity still in development, I shifted my focus to the new design system, taking advantage of the transition period before the CPO was fully onboarded. Starting with a foundational set of components and guidelines, I laid the groundwork for a scalable system that enabled high-fidelity prototyping and close collaboration with the Front-End team.

As development progressed, the design system evolved alongside it, expanding organically as new requirements emerged. Within a few months, it enabled us to build and test a fully interactive prototype of the MVP, which we used to gather feedback from the Visa team, key stakeholders, and potential customers.

Testing Use Cases

Having an interactive prototype of the full product enabled us to plan and run well-structured testing sessions with selected participants, covering the entire user journey from start to finish for the first time. Instead of allowing users to freely explore the application, we provided detailed instructions simulating real-world scenarios, which they were asked to complete independently, without external assistance.

By focusing on key flows, this approach would enable us to evaluate specific use cases and reduce biased or misleading feedback, helping us detect major usability issues and assess the overall user experience more effectively. From there, we were able to make well-informed decisions about where to prioritize our efforts and refine the product before moving forward with implementation.

Release and Validation

While the scope of a Minimum Viable Product (MVP) may vary depending on specific goals, its definition is rooted in the Lean Startup methodology, popularized by Silicon Valley entrepreneur and thought leader Eric Ries.

According to Ries, an MVP isn’t defined by a specific set of features or a fixed format—its core purpose is to test a product idea quickly and cost-effectively, gather feedback, and validate key assumptions before committing to full-scale development.

In that sense, each step of the product design process was approached as an MVP in itself—from day one to release, and beyond. The launch of our BNPL SaaS platform was just another step in the ongoing process of validating assumptions, testing the solution with real customers, and deepening our learning on the path toward product–market fit.

4. Design System & Organization

Strategic Planning & Execution

The transition from Paynova to Sileon opened a great opportunity to plan the new design system well in advance. Drawing on my previous experience with design systems, I was able to take a more strategic approach—bringing in best practices from the start, anticipating potential challenges, and prioritizing early collaboration with developers.

As with any product, having a dedicated team and resources for the design system is key, allowing continuous improvement, organic scalability, and keeping design debt to a minimum. I consistently advocated for this approach, encouraging involvement and co-ownership from the front-end team, and regularly communicating the system’s value and improvements during demo days.

Evolving with Figma

I kept up with Figma’s updates regularly—beta testing new features, contributing to the community, and attending Figma events. I pushed the tool to its limits to get the most out of it, and as Figma’s capabilities expanded over time, so did our design system.

Such improvements included adopting design tokens and variables, which enabled light and dark theme integration as well as dynamic prototyping, and integrating our design system with GitHub—allowing pull requests to be submitted directly from Figma, streamlining the handover process.

Overall, the design system became a cornerstone of our efforts to build user-centric products, foster a strong design culture across teams, and ensure a consistent experience throughout the entire Sileon portfolio. It provided a robust, validated framework that enabled rapid high-fidelity prototyping and accelerated iteration cycles.

Diagram illustrating the structure, core elements, key workflows, and the teams involved across the Sileon Design System.
This animation demonstrates the micro-interaction guidelines for the Toast Message component in Sileon’s Design System. It showcases two variants—manual and automatic closing—built in Figma using variables and conditional logic.
A visual representation of the different designer roles involved in the product development lifecycle.

Note: This infographic was created for a demo day presentation at Sileon to help stakeholders better understand the different design roles and their areas of expertise. Specialist roles are often combined (e.g., UX/UI Designer, UX Designer & Researcher), and the Product Designer role—while typically a generalist—can also specialize in one or more areas depending on the team, context, and experience.

The Design Team

From my first day at Paynova, I was tasked with laying the foundations for a future design team—a responsibility I carried forward as Sileon’s founding product designer. This goal shaped many of my early decisions, as I consistently planned with scalability in mind: streamlining collaboration, establishing best practices, and standardizing design processes to ensure a smooth onboarding experience for future designers.

As the workload and my responsibilities grew, so did the need to expand the team. In close collaboration with the CPO, we began identifying key needs and defining role requirements. I took the lead throughout the hiring process—regularly syncing with the recruitment team, selecting candidates, conducting interviews, and assessing fit.

As new team members joined, I took ownership of their onboarding—introducing them to our product portfolio and design systems. In addition to that, I provided ongoing mentoring when needed, evaluated their progress, and gradually delegated responsibilities to support their growth within the team.

5. Wrap Up & Handover

Leaving Sileon

After four intense and fast-paced years leading the design journey from Paynova to Sileon—and having played an instrumental role in building and launching a brand-new BNPL SaaS platform from the ground up—I felt it was the right time for me to take a break, close my chapter at Sileon, and finally commit to a personal project I had postponed for years.

To ensure a smooth transition, I prepared a comprehensive handover guide, documenting key processes, contextual information, design resources, repositories, the status of ongoing work, and recommended next steps. The material was clearly structured to support continuity and enable the incoming design lead to assume responsibilities with clarity and minimal disruption.

As the last remaining member of the original product team, I left with a sense of completion—setting the sails for a new, in-between chapter as a solo indie game developer. But that’s a story for another time.

“I can highly recommend Guillem for any Product design position. He is creative, delivery focused and very skilled and experienced product designer. He is customer-centric and always consider how to add value for the user. Furthermore, he takes on challenges with his solution-oriented mindset, which always lead to great result. On top of that, he is an excellent team member and appreciated colleague.”

Bahareh Zand, CPO at Sileon

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