STEM Career Tip: If you start your career at a small company where you are a "jack-of-all-trades" and the company doesn't succeed, you may struggle to package your work history. Although working across multiple departments is great experience, it can be difficult to convey this on your personal marketing materials. Unfortunately many people are categorical thinkers, and if they can't determine which department you belong to, they may disregard your application.
To have better success, focus your résumé largely on your STEM experience. Not only will this demonstrate the transferable skills for an engineering, IT, etc. position, but you will satisfy the ATS software. Reserve your cover letter for an explanation of how your dynamic experience will benefit the next company you work for.
As always, networking is key! Check your local business directory and create a list of all the companies might benefit from someone with your skill set. Reach out to people from these smaller companies, as they are more likely to value your ability to work across multiple roles.