In the driver's seat.
[Idiom] IN THE DRIVER'S SEAT. - Gain Control and Confidence in Life's Driver's Seat
Control the situation.
When someone says they are "in the driver's seat," they mean they are in control of the situation or have the upper hand. It derives from the literal act of being in the driver's seat of a car, steering and deciding the direction. In life, being in this position implies having the authority to make decisions and dictate how events will unfold, much like a driver controls their vehicle.
Example Sentences
She's in the driver's seat now that she's been promoted.
She's in control now that she's been promoted.
After winning the election, he was firmly in the driver's seat.
After winning the election, he was firmly in control.
With her promotion, she took control and confidently steed the company, finally in the driver's seat.
With her promotion, she took control and confidently led the company.