This year, rising interest rate risk, falling interchange income, increased employee compensation in a tightening labor market and even the emergence of Apple Pay will have an impact on how credit unions operate, according to Steve Rick, chief economist for CUNA Mutual Group. Despite an economically encouraging environment, hurdles will vary depending on the size of the credit union.

"With the economy and loan demand expected to be so good this year, it's hard to point to a lot of challenging issues CFOs will have to uniformly address in 2015," Rick said. "With each credit union so unique, advice that might work for one credit union may be completely wrong for another."

In some cases, those challenges may be a matter of degrees. At the $160 million West Community Credit Union in O'Fallon, Mo., size matters and so does liquidity. The ability to economically attract the funds necessary to keep the credit union's explosive loan program alive will be a major challenge in 2015, according to Jason Peach, the credit union's SVP and CFO.