Payment migration and integration | 24/7 payment processing support

Meet our client

Client

Ecommerce company

Product

Food box ordering solution

Project business goal

Grow user conversions and optimize costs through payment infrastructure revision

The project timeline in a nutshell

Chapter 1: Migration to 3DS payments

Implemented 3D-Secure (3DS) authentication across the platform and optimized its performance to enhance 3DS operations’ execution.

Chapter 2: PayPal integration

Introduced PayPal as a new payment provider to expand user payment options.

Chapter 3: Live user payment migration

Migrated card payments for 1.5M+ users from Checkout.com to Braintree (PayPal) on a live system with zero downtime.

Our client’s trust by the numbers

50,000+ daily recurring transactions
Engineering fault-tolerant payment infrastructure for continuous, error-free performance
$100 million processed per year
Handling high-value transactions with proven security and compliance

3D-Secure migration: where the collaboration began

“Our story began with the 3DS payment authentication migration. We inherited the project from another team during the first major migration phase. That handover gave us crucial insights into how the payment system was originally built and operated.
We worked closely with the original squad, especially as we transitioned from regular payments to 3D-Secure. It was a complex time — many feature components were being changed or newly developed, and we ran parallel streams for nearly six months. Eventually, we implemented robust 3D-Secure authentication to enhance payment safety and compliance and took over full ownership of the entire client’s payment system.”

— Oxagile’s team

Aiming to scale user conversions via PayPal integration

“Our move from Checkout.com to PayPal (Braintree) was driven by a few key hypotheses we wanted to validate. We believed PayPal’s out-of-the-box 3D-Secure setup — combined with their lightweight JavaScript SDK — could reduce friction steps at checkout and improve conversion rates. There was also a noticeable difference in transaction fees, which made the switch even more compelling due to its cost-effectiveness. While the cost benefits were clear, the real test was whether the smoother user experience would help us retain more users.”

— The client’s Project Lead

Strategic partnership: Oxagile leads payment processing

Expanded payment options via PayPal

Integrated PayPal as a new PSP to expand payment flexibility and improve checkout performance.

Real-time user migration at scale

Orchestrated a phased migration of over 1M users from Checkout to PayPal card payments; no service execution delayed.

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payment needs

Tech and strategic factors that impacted the migration

The transition to Braintree as the new payment gateway, while maintaining the existing one in sync, introduced a number of technical challenges we had to keep in mind.

Gateway abstraction
Token migration
User migration
Real-time risk

Gateway abstraction and custom integration

The client chose to build a custom gateway integration through a separate squad.
This added architectural complexity, requiring compatibility with both existing systems and Braintree’s API.
Ensured data integrity and system performance throughout the project delivery.

Token migration and payment chain validation

Migrated long-lived payment tokens from Checkout.com to Braintree.
Each token had to retain its link to a verified 3D-Secure transaction history.
Checkout stored critical authorization metadata, while Braintree needed to validate each token end-to-end before transactions could proceed.

One-time vs. chunked user migration

Faced strategic decisions on whether to migrate users in batches (chunked) or all at once.
Managing live user migration required balancing technical precision with operational continuity.
Ensured uninterrupted payment processing during the transition.

Real-time risk of blocking funds

Careful handling was needed to avoid triggering unnecessary holds on user funds.
Any token mismanagement could lead to failed transactions or account blocks.
Required precise rollout planning to protect user experience and trust — all while the system remained live.

Working in sync with the client’s product approach

Experimentation strategy

To improve paid subscriber conversion during signup, we implemented a controlled experiment using feature flags to release new ones to a limited number of users each month. Users were split between Checkout.com and PayPal flows, allowing us to compare conversion rates by payment provider.

PSP migration rollout

If an experiment showed positive results, the updated flow was expanded incrementally to more users. Once confirmed successful, the new flow replaced the old one entirely, ensuring continuous optimization based on real user data.

Ensuring payment continuity, 24/7

We introduced an effective payment support framework that brings clarity and control to complex system operations. By combining system playbooks, real-time observability, and automated incident response, we ensure rapid issue detection, reliable SLA coverage, and precise recovery objectives across every component.

Delivering results the client relies on

Accelerated payment gateway migration

We successfully transitioned from Checkout.com to Braintree within a focused three-month timeline, balancing speed with stability to minimize disruption.

Seamless live migration execution

All migration processes were executed in a live production environment, carefully coordinated to maintain uninterrupted payment operations for the active user base.

End-to-end support ownership

Following the PayPal integration rollout, we assumed full responsibility for technical support related to user payments, establishing a robust, always-on support framework to ensure reliability and responsiveness.

Is your payment infrastructure future-proof?

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Seamless payment migration and integration journey