Do I have any mistakes?

Hi Guys! I am supposed to write 10 sentences about my last job. I would be really happy to get your help!

Previously I worked at a boutique company named XXX.
XXX, founded 10 years ago, specializes in HR and offers their clients compensation and benefits solutions.
My position was Social Media Manager, which included creating the company's profile on Linkedin (business social network), creating and managing discussion groups, and creating and maintaining awareness of the service, mainly by uploading contents to the company's home page.
In addition, during my job I got an experience with building salary and bonus programs and benchmark analysis.

מצוין!

Do I have any mistakes?

Hi Guys! I am suppose to write 10 sentences about my last job. I will be really happy to get if your can help!

Previously I worked at a boutique company named XXX.

XXX was established/founded 10 ten [you need to spell out in formal English.  I did not correct the one in your first sentence because I consider that line an informal comment you made] years ago, specializing in at HR and offering to their clients compensation and benefits solutions.
My position was the Social Media Manager, which includes creating the company's profile on Linkedin (business social network), creating and managing discussion groups, creating and maintaining awareness of the service, mainly by uploading contents to the company's home page.
In addition, during my job I got an am experienced with salary building, salary and bonuses programs and benchmark analysis.