Any new versions or updates of the payment SDK, would have to be incorporated every time explicitly into the mobile application in all the platforms by the merchants.

A merchant will have to upload the updated version of the application in all the mobile application stores(Play store & App store).

All the end users of the merchants would have to update the merchant’s mobile application in order to use the latest features of the SDK

Failure to update either from the merchant or from the end user may result in failure of payment transactions.

The SDK UI had to be unaffected by the merchant page's stylesheet or javascript. Also it could not be developed using any existing popular UI frameworks like Angular / React JS as there could be conflict in case there is conflicting version found on the merchant's page.

The Web SDK also was not intended to be shown in an iframe which could have countered the problems.

TechBulls understood the core problem of the client which was the dynamic update of functionality without actually updating the SDK. We built the SDK using the Server Driven UI concept. Under Server Driven UI concept, the SDK was broken down into core components which the SDK binary implements and a dynamic template which drives how components behave and interact with each other.

The template allows you to display additional components to an existing screen, change labels, colors, placeholders, add new screens, change behaviour of a screen when a parti-cular button is clicked, introduce new valida-tions etc.

The Server Driven UI approach allows the client to maintain a single version of metadata that is template and ensure the same func-tionality across all the versions of SDK.

The Server Driven UI approach allows the client to maintain a single version of metadata that is template and ensure the same functionality across all the versions of SDK.

The level of flexibility achieved using the Server Driven UI approach is unpreceden-ted. Ratio of amount of code for SDK to Tem-plate is around 1:10. Concept of Shadow DOM was used to ensure the SDK UI is not affected by the stylesheet of the host as well as the host page stylesheet is unaffected by the stylesheet of the SDK itself.

We used Stencil JS to develop the Web SDK. It allowed us to create the SDK which was independent of any existing popular web frameworks or even Stencil JS itself.