Domain Experts / Subject Matter Experts / Industry Experts have invaluable knowledge that you can (and should) apply during your UX process. Domain expert involvement is not an alternative to UX research, and a domain expert is certainly neither a “user expert” nor a designer.
Interviews
Domain Expert Interview — UX Knowledge Base Sketches
Designers can have a more significant impact than pushing pixels and can help with the totality of what we produce. But this can only be achieved when product design is implemented from the start, at the strategy level.
Startups
How to Build a Bulletproof Product Design Strategy