I don't think tools, tech stack, or programming/scripting language matters here with respect to automating Workday. Any language, any tool, any test framework will do, choose what you are familiar or what seems easy to learn.
Rather I would envision what makes more sense to discuss is what techniques or methods of automation does one do interfacing with Workday. For example:
* how would you model the automation around specific UI pages or components/widgets in Workday (e.g. what kind of page object model implementation, or other type of modeling)
* how would you model/define the element locators of the elements within Workday UI (any tips/tricks to deal with tricky to identify elements)
* how would you handle specific features in Workday, that might have issues automating directly with Selenium APIs, like where you have to workaround by executing javascript code to invoke the desired functionality
those are certainly things that are more specific to Workday, and less so a generic problem of any web app.