FinTech · Engineering, no AI
Card payments moved to a new provider, live
Live card payments moved off one gateway onto another, with 3-D Secure added and payment tokens carried across, while the business kept taking orders.
- Client
- Ecommerce company running a food box ordering product
- Segment
- FinTech, payment infrastructure
- Timeline
- Gateway transition within 3 months
- Scale
- 50,000+ daily recurring transactions, $100 million a year
- 3-D Secure
- PayPal
- Braintree
- Checkout.com
- PayPal JavaScript SDK
- Feature flags
Before
What was true before
The client wanted more conversions and lower costs from its payment infrastructure. That meant adding 3-D Secure authentication, a new payment provider, and moving live card payments off Checkout.com. Token migration had to keep the link to verified 3-D Secure histories and could not block anyone’s funds while the system stayed live.
After
What we did
The team took over the 3-D Secure migration, added PayPal (Braintree) beside the existing gateway, compared the 2 flows with feature-flag experiments, and moved users across in phases, with 24/7 payment support and observability in place.
Build log
How it was built
- 01
Took over the 3-D Secure migration from a previous team, then took full ownership
- 02
Implemented 3-D Secure authentication across the platform and tuned its performance
- 03
Integrated PayPal (Braintree) as a new provider alongside Checkout.com
- 04
Migrated long-lived payment tokens to Braintree with token validation at each step
- 05
Split users between the 2 flows with feature flags to compare conversion
- 06
Rolled out the new flow in phases and migrated live users stage by stage
- 07
Set up 24/7 payment support with playbooks, real-time observability and automated incident response
Measured
Results
As reported in the published case.
- users’ card payments migrated with zero downtime
- 1M+
- for the gateway transition
- 3 months
- daily recurring transactions
- 50,000+
- processed a year
- $100 million
This engagement did not include AI. It is here as evidence of the engineering that AI work sits on.
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