The best QA designers approach every project with two things: an extensive toolkit and an open mind. They know that there is no single automated test system that can be applied to every situation. Every development environment is different, as is every domain and application.
The designer needs an extensive kit of technologies, tools, languages, and framework architectures to ensure they can build a successful system. They need the open mind to know which combination of those resources will work best under each new project specification.