Featured projects
Biometric Pay
Deploying a trusted biometric payment system under real regulatory and infrastructure constraints

Timeline

Apr–Aug 2022 (5 months)

Team

1 PM (me), 1 designer, 3 engineers

My Role

End-to-end Product Management from product discovery, stakeholder alignment, privacy framework, and cross-functional execution

Why this matters

This project showed how responsible deployment isn’t about avoiding constraints, but using them to make faster, safer product decisions that earn user trust.

TL;DR

Problem

Identified 7.5 daily hours lost to payment friction, reframing as an opportunity to deploy responsible biometric+payment integration

Strategy

- Rejected credit card infrastructure integration (2-3 years)
- Architected wage deduction integration (3 months) by separating databases, requiring verification, establishing opt-in consent
- Proving systems could integrate without breaking trust.

Impact

7.5hrs
Employee Productivity improved

Eliminated ~15mins of payment friction time daily

90%
Development Timeline Saved

Reduced dev timeline from 2~3 years to 3 months

0
Zero False payment charged

Implemented Trust-by-Design for trustworthy systems

+ Featured in Korean Science documentary!! (Nov 2022)

Context

People forgetting to take their cards when going to the cafeteria.

Employees frequently forgot their credit cards when visiting the in-office robotic cafeteria, causing repeated interruptions and productivity loss during peak hours. While employees were accustomed to frictionless authentication (mobile pay, face unlock), the cafeteria, however, depended on physical cards, creating repeated friction at checkout.

~10 incidents during peak times (3-4pm), ~30 incidents per day

~15 minutes lost per incident

~7.5 hours of productivity lost daily

Opportunity

Biometric Authentication could streamline the payment process.

Always available! No card or phone needed

Already familiar enough through everyday use from mobile devices, airport check-in, banking kiosks

Appropriate for frequent, low-value internal payments

challenge

How could Biometric Authentication be safely deployed for payments without eroding employee trust and reducing their frictions?

The real challenge wasn’t whether biometrics could reduce friction, but how to deploy them without compromising trust. Integrating biometrics with card networks would take 2–3 years and required external policy changes, unviable for an internal pilot. At the same time, biometric payments demanded zero tolerance for trust failures.

Infrastructure constraint

Integrating biometrics with card networks would take 2–3 years and require external policy changes, unviable for an in-house cafeteria.

Trust risk

A single false charge could permanently damage confidence in biometric systems.

Privacy & compliance

Biometric data required strict compliance with Korean PIPA ('Personal Information Protection Act’), explicit consent, and strong governance.

key decisions

How about applying an employee wage deduction system for the payment?

Delivered the same user value (cardless payment)

Reduced delivery time from years to 1 month

Avoided external dependencies and policy risk

Instead of using existing card systems, I proposed deducting coffee payments directly from wages when verified through the biometric data. This could be only deployed in in-house systems, but after strategic considerations, there seemed to be more potentials and benefits, while still solving the core user problems. This decision reframed a technical limitation into a responsible deployment strategy.

Solutions_Trust by design

Connected biometric authentication system to payroll database (only transmitting employee ID)
Biometric data are isolated from payroll systems and stored on premise as encrypted datasets.

Verification screen before every charge to avoid false payments

Explicit consent for authentication purposes during enrollment and 30-day deletion for inactive users

Defined industry-compliant biometric authentication threshold level of False Acceptance Rate for payment security

False Acceptance Rate: a security metric in authentication systems that measures the probability of an unauthorized user being mistakenly accepted as a legitimate user. Low is considered to be the secure system.

Solutions_New user Flow
impacts

To User

Eliminated Payment friction
15
min
False Charges that increase trust
0
min

To Business

Development Time Reduction
75
%
Cost Avoidance
90
%
Featured in the media!

[Special Feature] "Digital D.N.A." Part 2. Data.Network.AI. that makes money / YTN Science, YouTube Channel
Starting from: 18:27-Published: Nov, 2022Media: YTN Science, Korea

takeaways

✅ Reframing the technical constraint as a strategic opportunity

Instead of waiting years for card network integration, pivoting to wage deduction delivered user value immediately. This taught me that the "ideal" solution isn't always the right one, speed to value often beats.