It can be intimidating for inexperienced teams embarking on their test automation journey for an existing code base. There is so much to test, and so many ways to test. I often see teams stuck with debating on where to start and what tools to use and best practices: "We should start from unit tests" "No, integration tests are better!" "Should we use tool A or tool B?"
I see this play out all the time, and I've been there before. And the worst that could happen is decision paralysis and inaction.
The bigger question really is "What to test?"
My rule of thumb is ""Start with the scariest code"". I'll share with you my framework for evaluating the ROI of writing a test for a feature and prioritising what to test.
More details: https://confengine.com/selenium-conf-2020/proposal/13444
Conference Link: https://2020.seleniumconf.in