Moonshot. Merriam-Webster defines it as “an extremely ambitious project or mission undertaken to achieve a monumental goal.”
Swing for the fences. In baseball, this means to swing as hard as possible to hit a home run, which increases the chance of missing the ball. At work, it means to do something extremely ambitious, “especially rashly.”
Career-limiting move. This is an action that endangers “one’s future prospects of getting plum projects and raises, and possibly one’s job.” It is also called a CLM.