smart cookie (to be a) [exp]

Meaning:

• A person who is so smart and successful, and knows how to achieve a target.

Examples:

1. Leo won’t be deceived by these tricks. He is smart a cookie.
2. The new hire quickly streamlined the project workflow; she’s a smart cookie.
3. Don’t underestimate her during the debate; she’s a smart cookie.
4. He always knows the best deals online; what a smart cookie.
5. She figured out how to fix the software glitch in minutes. she’s really a smart cookie.
6. You won’t fool him easily; he’s a smart cookie.