checkered career
A history of employment characterized by many different kinds of jobs or by many alternating periods of success and failure. I had a checkered career after high school, taking any kind of work that I could find. I don't know if I would trust your finances to him, he's had a rather checkered career from what I've heard.
take the checkered flag
To finish in first place in an auto racing competition. (Spelled in British English as "take the chequered flag.") Primarily heard in US. Neck and neck right up until the final moments of the race, photo analysis revealed that it was Steinman who took the checkered flag.
checkered career
A background that includes many changes, especially of employment. For example, Heather's had a checkered career, hopping from one city to another and one job to another . This expression, first recorded in 1881, uses checkered in the sense of "constantly alternating," much like the squares on a checkerboard.