TICKETIER: Designing the checkout and installment flow for high-traffic ticket sales with ~98% payment success

Led the end-to-end design of the web and app checkout flow and visual guidelines, including a pioneering instalment feature, improving checkout conversion while maintaining a high instalment completion rate.

Futuristic shot of a male on o motorbike

GMM Company Thailand aims to develop an all-in-one ticketing application which is the first ticketing platform in Thailand to let users buy concert tickets in installments. At the same time, the new platform would leverage GMM’s strength in producing its own concerts and events, helping the company stand out from competitors in Thailand. My company, Omise, also proposed integrating Omise Payments to improve payment performance during the high traffic, especially when events open for public sales and purchase volume surges.

My main responsibilities and ownership were defining the full ticket purchasing UX journey from landing on the homepage through ticket registration for event entry, and creating the visual direction for the entire platform.

The first phase of the project ran from Q3 2023 to Q4 2024 and included a wide range of features. For this case study, I focused on the most impactful outcomes across the platform by highlighting the features where I had primary ownership, made key product decisions, and delivered measurable impact for the client, including:

The checkout payment flow
SmartPay (ticket instalments)
Visual design elements across the ticket-purchasing journey

The checkout payment flow
SmartPay (ticket instalments)
Visual design elements across the ticket-purchasing journey

Timeline

Q3 2023 - Q1 2025

Skills

UX Design UI Design Visual Design Maintaining the Design System

Client

GMM Grammy

My Role

Product and Visual Designer

Design Team

Product Designer: Watis Kotitrakool Junior Product Designer: Pichapong Harnpitukpong Design Manager: Ani Hovadanakul

Website

ticketier.com/home

Available on

Download on the

App Store

GET IT ON

What we wanted to achieve

Checkout reliability at peak traffic
Build a checkout that stays stable and reliable during high-traffic ticket drops.
Payment failure recovery
Reduce payment drop-offs by designing clear handling for common failure cases (e.g., issuer decline, timeout, gateway/server issues).
Conversion through instalments
Improve conversion by offering instalments as a lower-friction alternative to paying in full upfront.
Installment completion and recovery
Help users complete recurring instalments with transparent schedules, clear expectations, and recovery flows for missed payments.

Key solutions

Designed the main checkout flow to support high-traffic ticket sales, with transparent fee breakdowns and clear visibility of all available payment methods.
Provided immediate, user-friendly error feedback with clear language to help users understand what happened and what to do next.
Designed error and failure scenarios as guardrails for system or payment failures, helping users recover smoothly while protecting their ticket reservation.
Designed the installment flow to clearly show each payment step, including payment status and upcoming due payments.
Provided flexible repayment options, allowing users to pay either the outstanding installment amount or the full remaining balance.

Final outcome

The main checkout flow addressed key payment issues, and we worked closely with backend developers to understand the payment flowchart and API constraints.
The instalment feature aligned with the same payment-status visual language, helping users navigate each instalment cycle through the main feature screen.

Impact delivered

Business impact

Payment Success Rate (PSR): ~98.7% (3,000 successful orders vs. 40 failed).
Payment Failure Rate: 1.3%
Checkout conversion for ticket installments: ~90%.
Instalment opt-in rate: ~80% of purchasers chose instalments over full payment.
Installment completion rate improved from ~70% to ~95% after the new instalment experience launched (+25 percentage points)

My delivery performance

Delivered design tickets against sprint goals and plans with an 82% success rate per sprint.
Achieved 81% CSAT for design quality and client review sessions.
Maintained 92% story point estimation accuracy each sprint.
Reduced back-and-forth and rework, keeping clarification cycles to no more than three.