Pi (파이) is Hanwha Life's custodial investment app for families who want to invest for their children through tax-exempt gifts. During my internship with Hanwha Life’s Wealth Product Team, I reframed and redesigned a web gift investment simulator as an in-app growth planner that helps Korean families plan tax-exempt gifts for their children.

Note: Prototypes and designs presented are English adaptations of the Korean implementation for a clearer explanation.

Context

Long-term investing has been gaining ground with the Korean public, and that includes parents who want to start early for their children. Every 10 years, a child can receive a set amount from family without any gift tax. Pi lets families invest those gifts in a custodial account and digitally report them to the tax office without leaving the app.

To promote Pi, the team had built a web Gift Simulator. Anyone could open it in a browser and see how quickly tax-exempt gifts could grow if they were invested for a child starting today for 30 years.

Problem

On the web, the simulator spoke in general terms with example numbers based on the input birth date. Inside Pi, the app knows each child's real age and the gifts the user had already reported through HomeTax, Korea's online tax service.

The question now shifted from "How big could my investments potentially get?" to "What can our family currently give this child, who can give it, and when next?"

The task was then to bring a browser feature into a mobile app and turn these overlapping timelines with complex numbers into something a parent could easily follow on a phone, for their own child.

Process

I utilized feedback from actual users of the app to guide the direction

Since this feature's intended user switched from primarily non-users to real users of the app, I requested logs of customer service requests and looked at app reviews to guide what other pain points this feature could solve.

Users wanted:

• A better breakdown of the numbers and information. Users had a hard time still understanding how all of this works even after gifting due to the complex nature of finance laws and regulations

• A more approachable experience. Given that the app is a family wealth app, users expressed that they wanted more family-friendly content or visuals

• More personalized tools and features. Although the app provides personalized gifting limits and tax reporting workflows, there wasn't a feature to answer "what next?" and "when next?" after they gifted within the limit.

This process was especially helpful for me to understand how to build a feature that users would want to use. My first couple renditions and ideas were still similar to the original simulator, as I prioritized information integrity.

However, through user analysis and data, I found that the bigger priority was ensuring clarity and learning through enjoyment. I broke the initial prototype down into several screens and built the information up sequentially to prevent information overload.

I built user personas to accommodate for different user types

Some users were completely new to the app while others were investing for their children before the app was released. I wanted the feature to provide a specific, personalized timeline to help prepare not only for the present, but also the future.

We built the solution around 4 main personas based on demographic data provided through the app.

Read more about the personas here

Solution

Swipeable timeline with one stop per tax-exempt window

Each stop is one 10-year window and shows the child's age, how much the family can still give, and the child at that age.
Small tags on the line open short explanations for the overlapping Minor/Adult Allowance windows that start when the child turns 19.

Built for one phone and one family

Planning a stage goes Mom & Dad → Grandma & Grandpa → other relatives, then a growth speed, then the result. Best Plan fills the remaining allowance automatically, using the 3% monthly-gift discount.

When one side of the family has used up the shared allowance, the next screen says so plainly and explains why, instead of letting a grandparent enter an amount that would be taxed.

Numbers you can trace

The full plan breaks the result down by allowance window, giver, and return, so users can see how the total was built.

Plain language for complicated numbers

Each rate of return is a vehicle and comes with details about what's inside it and how bumpy the investment can get. Formal terms moved into the detailed explanations, so families recognize them when they see them again through HomeTax or the tax office.

Outcome

A new conversation about usability

Leadership had mostly measured the app by usage and retention. Walking them through the planner with real family situations, like a grandparent who can't give because the parents already have, or twins who aren't born yet, shifted the conversation. Usability and personalization started being discussed as priorities for an app meant for very different families.

A reason to open the app between gifts

Before, Pi was somewhere you went to invest and report a gift. The planner gave families a reason to come back in between. Users told us they could see their plan, their remaining allowance, and their next window without working it out themselves outside the app. Parents who had given before joining Pi also found a use for it, as a planner for when their current tax-exempt window runs out.

Learning as a next step

The planner ended up teaching families how gifting rules and custodial investing work, almost as a side effect. That led the team to discuss building dedicated learning features alongside it.

Reflection

Preparing this case study, I adapted the prototype into English, and found myself solving the same problem a second time. Terms that had been simplified for Korean parents needed simplifying again for readers who've never heard of HomeTax or a 10-year gift window. "Tax-exempt allowance," "Mom & Dad," "growth speed" each was a small decision about balancing what a reader needs to know right now and what can wait for the details.