Refining Key Interactions in a Retail POS System (Pre-Launch Pilot Phase)

Kiss Retail Solutions
Scope: Interaction Design, UI Refinement (Pilot Phase)
Year: 2026


Context


  • Newly developed POS system for beauty retail stores
  • Joined mid-project prior to launch
  • One-store pilot feedback surfaced interaction friction
  • Focused on refining high-frequency retail interactions


Problem


Retail POS systems operate in high-frequency, high-pressure environments.
During a pre-launch pilot with one beauty retail store, we identified several interaction frictions that disrupted transaction flow — particularly in dual-screen interactions and input-heavy moments like PIN entry and customer data collection.

Although the core system architecture was already defined, small inconsistencies in interaction patterns created confusion between staff and customer screens. In a retail environment, even minor friction can slow transactions and increase input errors.

Our challenge was not to redesign the entire system, but to refine key interaction points before launch to improve clarity and continuity.

Key Interaction Decisions

Transaction Interruption Pattern

We evaluated whether validation states should interrupt checkout with a full-page error view or preserve flow through modal overlays.
We used full-screen warning modals instead of bottom snack messages to ensure critical alerts were immediately noticeable and clearly acknowledged.

Before: Full-page interruption during checkout

After: Modal overlay preserving checkout continuity



High-Frequency PIN Input Optimization


Pilot feedback surfaced issues with small button targets and lack of tactile feedback during PIN entry.
I increased button target size and introduced clearer input feedback cues to improve accuracy and confidence in rapid, repeated transactions.

    Before: Small target size in high-frequency interaction

    After: Enlarged touch targets for accuracy


    Dual-Screen Role Clarity

    When collecting customer credit information or email addresses, input shifted to the secondary display for customer entry.
    To avoid confusion, I designed synchronized state messaging on the staff-facing screen (e.g., “Customer entering information”) to maintain clarity and prevent premature actions.
    This reduced ambiguity between staff and customer roles during shared interactions.

    Synchronized “Customer input in progress” state


    Customer-side input interface



    Outcome


    These refinements:
    • Improved clarity during live transaction scenarios
    • Reduced ambiguity across dual-screen interactions
    • Increased input confidence in high-frequency checkout moments

    While incremental, these changes strengthened the system’s real-world readiness ahead of launch.