Building the missing interface for a fintech lending product
- Company
- OatFi
- Role
- Sole product designer, 15 months
- Industry
- Fintech · Embedded Lending
- Timeframe
- Jul 2022 – Sep 2023
Challenge & context
OatFi had a lending engine and no way to show it. The product was an API. No interface, no dashboard, nothing a non-engineer could look at and understand.
Three audiences needed the product to work for them, and none of them had anything to use. Internal admins configuring partners and lending rules. Partner admins monitoring their own programs. End users applying for loans without ever knowing OatFi existed.
Key challenges
- Every sales conversation required an engineer in the room.
- Every operational change required the CTO writing custom database queries.
- Growth and operations were both blocked by the same bottleneck: engineering bandwidth.
Role & scope
Sole designer, end to end
15 months, part time. Full ownership across all three product areas: internal admin, partner admin, and end-user loan flow.
Direct access to leadership
Worked directly with the PM, the CTO, and the CEO. Around 10 fullstack engineers. Lean team, high autonomy.
Research under constraints
Competitive research on Stripe and Plaid, stakeholder interviews, and close attention to founder feedback after every sales demo.
What I led
Three experiences, not one
The default path was a single product with role-based permissions to hide features per user type. I pushed back. Internal admins think in terms of configuring the system. Partners think in terms of running their business. Same data. Completely different mental models. I proposed three connected experiences sharing a foundation (same components, tokens, and patterns) but with different navigation, information hierarchy, and surface area. Permissions shaped the entire experience, not just hid buttons. That decision came from working sessions with the PM, stakeholder interviews with the CTO and CEO, competitive research on Stripe and Plaid, and paying close attention to founder feedback after every sales demo.
A contextual side drawer for seamless integration
The end user applies for a loan on a partner's website. Trust is fragile at this moment. I explored three patterns. A full page redirect makes the user feel like they left. A modal fails on mobile. A side drawer keeps context, feels native, and collapses into a bottom sheet on mobile. The drawer won because it solved for context, trust, and responsiveness at the same time. I designed every state with the same care. Approved is the easy screen. Declined had to feel respectful. Underwriting delayed had to communicate progress without making the user feel abandoned. In lending, edge cases are where trust is built or broken.
Prototypes that could sell
With no working product to demo, I built interactive prototypes showing the end to end experience across all three audiences. The CEO and CTO used these directly in sales meetings, closing over 10 enterprise deals without needing an engineer to explain the product.
A design system that let the work outlast me
OatFi had never had design standards. Every feature started from scratch. I established the first design system as the infrastructure that made the three experiences possible. The component library and documentation gave engineering a shared language and gave the PM the ability to make consistent UX decisions when I was not available. Features shipped faster because components did not need to be reinvented. The system changed how the team worked, not just how the product looked.
Impact & evidence
- 10+ enterprise partners closed using interactive prototypes, no engineer in the room.
- Internal team became self sufficient: onboarding partners, adjusting lending caps, and managing settings without engineering.
- Established OatFi's first design standards, giving the PM a framework for consistent decisions even after I was no longer available.
- Three tailored experiences on a shared foundation serving all three audiences.
“Gil was instrumental in defining the structure and layout of our platform, making complex workflows intuitive despite the depth of the data. He set clear design standards and worked closely with engineering to ensure the design system was implemented consistently. His thoughtful use of UI patterns reduced clicks, simplified workflows, and greatly improved user confidence.”
Paola Calderón - Product Manager
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