The content originally appeared on: CNN More from Success People are walking away from their jobs in droves, with a record number of workers quitting their jobs last year, according to the Labor Department. And with nearly 11 million job openings at the end of December, companies are having a hard time hiring - and keeping - employees. 'This is the most challenging environment I've ever encountered, both in terms of recruiting and retaining,' said Doug Brien, co-founder and CEO […]