Case study · Fintech · Mar – Jun 2026
Tefi — making money feel human.
A financial education app designed from zero for people who were never taught about money. Today it's live and sold to companies in Uruguay as a benefit for their employees.
- Role
- Lead Product Designer (freelance)
- Timeline
- Mar – Jun 2026, with weekly reviews
- Scope
- Brand, information architecture, design system, B2B + B2C screens, prototypes, handoff
- Worked with
- The founding board and the development team
Live
and sold to companies as an employee benefit
290+
B2B screens
55+
B2C mobile screens
82
component variants in the design system
01 · The challenge
Money is personal. Most finance apps aren't.
Tefi teaches financial education to people who had always been far from it. The product had to talk about money, debt and spending without judging, and be simple enough for anyone to follow.
- Sensitive topicsDebt and overspending carry shame and anxiety. A cold dashboard pushes people away.
- An audience new to financeMany users had never budgeted. Every screen had to be easy to understand on the first try.
- A board outside techThe founders weren't from the tech world, so they needed to see and use the product to make decisions.
02 · Key decision
I proposed rethinking the brand from the ground up.
Tefi already had a brand manual, but it didn't fit the conversations the product needed to have. I proposed changing the colors radically, adding a mascot and building the whole experience on emotional design: a companion that makes talking about money feel safe.
03 · The mascot
Meet Tefi, a companion for every money moment.
22 expressions so Tefi can show up in the right mood: celebrating a saving goal, studying with you, or sitting with you when the numbers are hard.
04 · Process
A roadmap, reviewed week by week.
I set a roadmap of a few months and presented progress to the board every week, so each decision was validated before building on top of it.
-
01 · Brand
New palette and the mascot
First I presented Tefi and the new colors, the emotional foundation of the product.
-
02 · Structure
Information architecture in low-fi
Wireframes for the whole app. Once approved, I made sure the structure would scale before any visual design.
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03 · System
The design system
Tokens, components and variants for B2B and B2C, built on top of the approved structure.
+ Claude for the system -
04 · Screens
High fidelity, section by section
Each approved section went from low-fi to final screens on top of the system.
+ Claude for screens -
05 · Prototypes
A working prototype per section
After each section, a functional prototype the board could click through instead of imagining.
+ Claude for prototypes -
06 · Handoff
Ready for development
Final screens, components and specs handed off to the developer.
05 · How I used Claude
AI for speed. Judgment for the decisions.
From approved structure to a full system
Claude helped me turn the approved architecture into tokens, components and variants for two products.
Low-fi to final, faster
Section by section, Claude helped take my low-fi wireframes to high fidelity using the system we had built.
Something the board could touch
Claude built a functional prototype after each section, so non-technical founders could use the product and decide with confidence.
The brand direction, the structure and what to prioritize were decided with the board. AI made each step faster; it didn't make the calls.
06 · The product
Every screen designed to feel like a conversation.
- A companion, not a judgeNo red number appears without context: Tefi always adds a suggestion or a message.
- A soft entry to hard topicsConversations about debt and overspending start with Tefi introducing the topic.
- Progress over perfectionLevels celebrate small improvements and never compare users to a perfect profile.
- Tone of voice as designEvery microcopy sounds like Tefi: warm, direct and never condescending.
07 · Designed to grow
Gamification, planned beyond the MVP.
To keep people coming back to complete classes, I designed a points, levels and achievements system. It wasn't part of the MVP: it's planned for V1 and V2, and the design system already supports it.
- Levels
- Points
- Achievements
- Financial games
08 · Outcome
Live, and in companies' hands.
Tefi launched and is now sold to companies in Uruguay as a financial-wellbeing benefit for their employees.
Try it yourself
What I learned
- Show, don't describeWorking prototypes made each decision concrete for a board outside tech.
- Structure before pixelsApproving the architecture first made the system and the screens much faster to build.
- A good system makes AI usefulWith clear tokens and components, Claude produced screens that were consistent from the start.