Case study
Embedded online banking integration
A third-party financial product embedded inside an existing online banking application.
My role
I led the production launches and managed the authentication workflow between the online banking platform and the embedded application.
The constraint
The product ran in an iframe, and third-party cookie restrictions broke session creation in some browsers, particularly on Apple devices using WebKit.
The initial implementation worked in some environments but failed where browsers restricted third-party cookies. That made the issue look inconsistent until the behavior was compared across browser engines and device types.
The decision
I reproduced the failures across browsers, traced them to the cookie dependency, and worked with the vendor to change how sessions were created. I also advised the vendor on authentication for its server-rendered application.
- Online banking
- Platform SDK
- Embedded application
- Vendor service
The important change was moving session creation away from a browser behavior the embedded application couldn't reliably control.
Outcome
The product launched inside online banking with an authentication and session approach that didn't depend on third-party cookies.
Stack
Python, HTML, CSS, JavaScript, Server-side rendering, iframe messaging