Pennywise, Effortless Expense Tracking

A time-boxed budgeting concept designed to make daily spending easier to understand and act on.

10 min read
Context
Walmart's Sam's Club interview exercise
Duration
14-hour design sprint
Role
Product Designer
Scope
Mobile app and organizational design

Overview

The brief was intentionally broad: design a budgeting app. I developed Pennywise as a mobile product that helps people set budgets, understand category-level spending, review transactions, and build stronger financial awareness.

This case study came from a 14-hour design sprint. The ideas capture an initial product direction and would need deeper research, validation, and iteration before production.

The brief

What the experience needed to support

With limited time, I used secondary research to define the core user goals that would guide the concept.

Five questions shaped the task

  • How can someone set up a budget without unnecessary effort?
  • How should the product reveal consistent overspending or underspending?
  • How can spending across a period be understood relative to a budget?
  • How can someone inspect the transactions behind the summary?
  • What should the product consider after an initial MVP?

Goals from secondary research

  • Set up budgets easily and intuitively.
  • Visualize spending by category.
  • Review the detail behind individual expenses.
  • Develop a clearer sense of financial awareness.
  • Use that awareness to plan ahead.

The approach

Ground the sprint in one realistic routine

I moved from a research-based persona to a day-in-the-life flow, then translated the friction in that flow into product requirements.

Dhruv is a 28-year-old software engineer who recently moved to Bengaluru. He is comfortable with technology, busy at work, socially active, and mindful about saving, but finds mental calculations and spreadsheets slow and unreliable.

What he wants to do

  • Track everyday treats and coffee.
  • Adjust transport and dining budgets.
  • Make informed grocery purchases.
  • Keep entertainment spending within limits.
  • Check his finances before spending.

Why it matters

  • Stay in control of spending habits.
  • Save for investments and future goals.
  • Avoid spending beyond his means.
  • Understand his financial health.
  • Feel organized and proactive.
The day-to-day flow used to locate budgeting friction and decision points.

Where the friction appeared

  1. 01
    Morning coffee

    Dhruv wonders what a small daily indulgence adds up to over time.

  2. 02
    Commute and lunch

    He chooses cheaper options without seeing the budget he is trying to protect.

  3. 03
    An unexpected bill

    An SMS prompts mental arithmetic across utilities and other expenses.

  4. 04
    Groceries and an evening out

    Unclear limits make him second-guess both purchases and time with friends.

  5. 05
    End-of-day reconciliation

    Receipts and spreadsheet updates turn financial awareness into a nightly chore.

Pain points

Translate frustration into requirements

The concept needed to account for the full set of issues surfaced in the exercise.

  • Complexity: a steep learning curve makes a finance app hard to adopt.
  • Slow data entry: logging many transactions manually becomes tedious.
  • Inaccurate tracking: expenses can be difficult to categorize correctly.
  • Limited customization: a single model does not fit every budget.
  • Security concerns: financial data requires strong user trust.
  • Poor integrations: disconnected accounts create incomplete information.
  • Notification overload: too many low-value alerts quickly become noise.
  • Limited reporting: weak reports obscure the full financial picture.
  • Lack of guidance: some people need help deciding what to do next.

The concept assumes accurate transaction data, advanced integrations with banking partners, and access to financial experts. These assumptions would require validation.

App walkthrough

A minimal budgeting companion

I named the app Pennywise and kept the interaction model focused on quick understanding, lightweight input, and progressive detail.

Open the end-to-end Figma prototype
Pennywise begins with a lightweight, friendly introduction.

01 · Onboarding

Start with lifestyle, then shape the budget

After account setup and bank linking, the user shares information about their lifestyle. Albert, an in-app concierge, uses that context to personalize guidance and preselect relevant interests such as dining out, cabs, and groceries.

The user can add more interests, and categories can be created or removed later. A future version would also support fully custom interests and categories.

The selection screen spans everyday categories such as groceries, dining, transport, rent, subscriptions, utilities, investments, entertainment, and travel. This gives the setup room to reflect different lifestyles without forcing every category on every user.

On the final onboarding screen, budget amounts can be adjusted with sliders. Albert prefills them from income information available through connected accounts, reducing the need to enter and maintain separate income records.

The example starts from an income of ₹80,000 and proposes amounts across groceries, transport, utilities, dining, rent, and investments. These figures make the adjustment model concrete, but remain illustrative values within the sprint concept.

Lifestyle input, suggested interests, and adjustable category budgets.

02 · Home

Show the financial picture at a glance

The home screen uses cards to show spending for the day, overall budget usage, and category-level budget usage. A central plus action makes expense entry easy to reach.

In the example, ₹860 has been spent today across groceries, transport, and a smaller discretionary purchase, while overall budget use is shown at 85 percent. Category cards use circular indicators to make the relative state easier to scan.

Because people often log a purchase while moving, the first sheet asks for only the essentials. Dragging it upward reveals the additional fields when more detail is useful.

A quick overview paired with progressive detail during expense entry.

03 · Categories

Make each budget understandable in one view

The category screen brings the amount spent, comparison with the previous month, and current budget consumption into one top card. A circular chart makes consumption easier to scan than a number alone.

The groceries example shows ₹2,100 spent this month, a comparison with ₹3,200 in the previous month, and 38 percent of the category budget used. A transaction list adds the detail behind that summary, including D-Mart, Reliance Fresh, Big Bazaar, More, and Spencer's.

People can move between categories by holding and swiping the bottom control, or by tapping either side one category at a time.

Category detail combines progress, comparison, and recent transactions.

04 · Spend details

Keep the list light until detail is needed

Tapping any transaction opens a full-page sheet with the additional information for that expense. The pattern keeps the category view scannable while making deeper detail one action away.

The demonstrated transaction is a ₹220 D-Mart grocery purchase. The expanded view adds the date, connected savings account, card reference, location, and a receipt upload.

Transaction detail appears only when the user asks for it.

05 · Trends

The Trends screen gathers the most useful reports and data points so users can move from checking individual expenses toward understanding patterns in their financial behavior.

The February example compares planned and actual spending across groceries, transport, utilities, dining, and rent. It also surfaces overall budget usage, the highest-spend category, and a daily spending chart.

Reports help connect daily activity to broader spending patterns.

Sponsors and monetisation

Explore revenue without hiding the tradeoffs

The sprint considered two possible models. Albert could be supplemented or replaced by subscription access to financial experts, and brand partnerships could support carefully selected notification campaigns.

The subscription screen proposes expert-created strategies and daily money tips. Its 300k+ social-proof line is concept copy, not a measured Pennywise outcome. The sponsored examples are visibly marked as ads and explore lending and travel partnerships.

Both ideas would need testing for usefulness, trust, and notification quality before becoming part of the product.

Early concepts for expert subscriptions and brand-supported communication.

Organizational design

The team and rhythm behind the product

The second part of the assignment asked how I would structure the team responsible for developing the product beyond the sprint across web and native platforms, using an assigned budget and a clear prioritization model.

Core team

  • Product designers.
  • Frontend and backend developers, or full-stack developers.
  • Quality assurance.
  • Product manager.
  • UX researchers and UX writers when budget permits.

Working process

  • Two-week sprint cycles with a maintained backlog.
  • Daily standups to identify blockers.
  • A weekly retrospective to track progress.
  • Direct customer conversations for every team member.
  • Product, design, and engineering rotating through support tickets.
Open the project whiteboard

Reflection

A direction to validate, not a finished answer

The sprint connected a broad brief to a specific routine, a complete product flow, and a practical delivery model. Its strongest ideas are quick financial understanding, progressive expense entry, and personalized setup.

The next step would be primary research with people who manage budgets in different ways, followed by usability testing around account linking, category setup, alerts, and trust in automated recommendations.