As you can imagine, securely hosting critical and often sensitive data in remote locations to be accessed by users potentially around the world is a monumental challenge. In fact, if the activities involved with cloud computing aren't secure, then cloud computing not only can't function, but it can cause a tremendous amount of damage as we have seen with a number of data breaches over the years.  
The end result is that companies place significant value on candidates who have experience and / or certifications associated with security including the following:  
Certificate of Cloud Security Knowledge Certified Cloud Security Professional Certified Integrator Secure Cloud Services CompTIA Cloud + Professional Cloud Security Manager 
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Now, there's no hardcore prerequisite for professionals to be certified from any of these cloud providers, but if they are certified, they can be called Solutions Architects, Cloud Developers, or SysOps Engineers, depending on the certification. Regardless of the title, However, the main job roles and responsibilities of a Cloud Engineer remain the same.

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