Toss Bank Reveals Design Philosophy Behind 'Locked Piggy Bank' for Teen Savings

Juyeon Oh, a product designer at Toss Bank, shared the design background and principles of the 'Locked Piggy Bank' feature, developed to help teenage users build savings habits. Teenagers tend to experience repeated savings failures because their reward systems are developed while their prefrontal cortex regulation remains immature, necessitating a mechanism to help them stick to goals they set themselves.

Design Principles and Interaction

The initial idea of 'breaking the piggy bank' was excluded because, although fun, it could induce feelings of failure. Instead, an unlocking method involving pressing and holding a button for a few seconds was adopted based on the following three principles:

• Fair difficulty: Designed so that accessibility does not vary based on cognitive ability or dexterity
• Elimination of guilt: Removal of staging that emphasizes failure or punitive elements
• Guaranteed autonomy: Maintaining a path to access one's own money without needing permission from others

UX Philosophy

Soft visuals and gradients were applied to ensure the locking mechanism feels like a 'device that upholds resolve' rather than a 'blocked door.' This case offers insights into fairness, emotional impact, and agency that should be considered when designing products that intentionally introduce friction for the user's benefit, such as focus modes or app locks.