Dear XCorp / Hi, XCorp depending on familiarity
I'm writing in response to X, where you advertised a vacancy for Y. I am interested in applying for this role -- please find my CV attached.
My current employment position is X, which means I'm responsible for delivering/organising/producing A, B, and C. I was previously the Y at Z where I did D. My main responsibility / largest project here has been P, which is a Widget that produces Doo-dads.
While I enjoy working at X for reasons K and L, I find M frustrating. I'm also looking to move on into areas such as N, P and Q, without losing touch with K. I find K valuable but I would prefer to change my working environment to include P.
I'm particularly interested in XCorp because, as well as providing the career experience I'm after, I use your product / admire your work / look up to your staff for these reasons: ...