Graphic Design Manager Job Description

How to efficiently describe your job on a resume when you wear many hats?
How do you determine what’s worthwhile & what’s not?
Example:
Job description:
Company,2004-Present
Graphic Design / Marketing Manager / Purchasing / IT Specialist / Customer Service
Responsibilities –
Created and maintain website & product catalog
Maintain & troubleshoot internal network & technology problems
Maintain POS database & reports
Office inventory purchasing & management
Customer service
Mention each one and a brief history on them with references for all.
Technology and Engaging Audiences – Walker Blog Examples