Everything is Design, everything!
As Paul Rand said, in an exalted way and he said most of the things he said": “Everything is Design, Everything!”
Design is the creation of something to solve a problem. Sometimes the problem is concrete — Users can’t log out. Sometimes the problem is broader — Users don’t trust your brand. The Design can include an interface, brand colors, a logo, a strategic thinking…
What the above have in common is that all are problems that good design is intended to solve. If you have the ability to solve problems, to evaluate them. To propose solutions, to think through a process of solution and building things…then in a practical sense, you have a designer layer in you.
Now, you may not be the best designer or not have the expertise to translate your thinking into actionable, tangible solutions. If this is case, and you are intending to work with someone that is a GOOD designer, you can trust them, and their opinions, and their explanations. They have dedicated and proven experience in solving these sorts of problems. Not trusting them is missing a golden opportunity to improve and optimize your Team efforts.