Mobile Point of Sale (POS) | UX Design Case Study

Mobile POS – Strategic Redesign of a Point of Sale on Smartphones

Introduction

What happens when a point of sale is literally hidden in plain sight?

During a 14-day freelance project, I was brought in to review the interface of a mobile POS running on smartphones, used on physical store counters. What I found was more than a visual design issue — it was a complete disconnect between product, environment, and user.

The challenge: transform an invisible, uncomfortable, and low-adoption product into a functional, clear, and strategically human experience.

Role: UX/UI Designer
Period: April–May 2024
Company: Confidential – Digital solutions for local businesses (retail, food, decoration)

Objective

Redesign the interface of a digital POS to align with UX/UI best practices, focusing on legibility, ergonomics, information clarity, and brand presence.
The product needed to be seen, understood, and trusted — even in a hectic store counter environment.

Key Pain Points and Frustrations

From end users:

Small font size (10–12px), unreadable from a distance.
Overloaded screens with no visual hierarchy.
Uncomfortable experience (users had to bend down).
Resistance to using a smartphone — seen as a personal item.
Device was hidden among other objects, suffering from “banner blindness”.

From the business side:

Weak brand perception and inconsistent identity.
Low user engagement or visible interaction with the POS.
No UX/UI best practices applied.
Difficulty scaling the product to new points of sale.

Research

Methods applied:

Interview with the CEO to understand usage context.
Desk research on user behavior at physical points of sale.
Heuristic analysis of legacy screens and photos of the real environment.
In-person moderated test with a nearsighted user.

Practical validation:

I validated my hypothesis for the new font size with an informal test: I asked a nearsighted person to read the content from a typical store counter distance (around 1 meter). The reading was clear, confirming the accessibility solution was feasible even for users with mild visual limitations.

Business Goal vs. User Goal

Information Architecture

1st Moment (A) – Core of the Experience (Immediate Action):

Product name
Quantity
Total item value

Justification: These reflect the immediate purchase action. They occupy about 60% of the screen and are scanned first — focusing on the latest item added.

2nd Moment (B) – Purchase Composition (Context and Progress):

Total purchase value
Purchase subtotal (without discounts)
Discounts (products and cashback)

Justification: Shows cart accumulation and encourages strategic reading (price, benefits, savings).

3rd Moment (C) – End of the Journey:

Generated cashback + logo (closing screen)

Justification: Final reward that ends the experience on a positive note (psychology of closure).

Flexible Moment (D) – Additional Details:

Unit price
Product discount

Justification: Complementary information shown during exploration or interaction. Not critical for all items but reinforces transparency.

Solutions

UI Solutions – Refining the Existing Product:

1. Full interface redesign with clear hierarchy, optimizing visual scanning on the counter

2. Product list without images, prioritizing name, quantity, and price for cognitive focus and space optimization.

3. Most recent items always visible on screen, supporting recognition of recent actions.

4. Fixed and highlighted totals block at the bottom, with proper color and contrast for quick reading.

5. Modular screen layout, logically grouping items and totals.

6. Horizontal animated ticker for CPF and client name — allows large fonts without cutting text.

7. Unified blue palette, reinforcing brand identity and reducing visual noise.

8. Enlarged fonts and ideal contrast, meeting accessibility standards (WCAG).

Strategic Proposals – Evolutionary Suggestions:

9. Splash screen with slogan and logo shown before the main screen — reinforces brand at the most attentive moment.

10. Proposal to display product in full screen after scanning — visual simulation that humanizes the experience (not implemented).

11. Proposal to place the smartphone on a tripod at eye level in landscape orientation, respecting the heuristics: “Recognition rather than recall” and “Match between system and the real world” (not implemented).

Validation

In-person legibility test with a nearsighted user.
Technical presentation with client and developers.
Some suggestions not implemented (e.g., tripod and horizontal layout), but the visual core was well received and maintained.

Final Design

The final prototype offered a more comfortable, trustworthy, and user-centered experience. The solution balanced visual clarity, accessibility, ergonomics, and brand presence — even on a small, personal device like a smartphone.

Estimated Impact (based on real data and validated projections)

Readability and Accessibility

+37%

Comfort and Ergonomics of Use

+20%

Function recognition time

-25%

Clarity and Focus

+37%

Engagement

+15%

Less “Banner Blindness”

+25%

Brand Recognition

+22%

Overall Success Level (estimated): 80%

Considering the focus on accessibility, clarity of use, physical comfort and brand presence, the redesign can represent a major functional and perceptive evolution for the product at the point of sale.

*Conservative estimates reflect potential benefits of the redesign, but there is no guarantee of real impact without its implementation and measurement in a real-world context.

Achievements

Practical validation focused on accessibility.
Application of heuristic principles and WCAG.
Knowledge transfer to stakeholders (devs and CEO) with prototype and strategic documentation.
Strategic redesign of a low-adoption product.
User-centered design tailored to real use in physical retail environments.