A core system is essential and should deliver the needed featuers and services credit unions require. When shopping for new core technology, it is wise to primarily focus on the features and benefits the core system delivers. However, a secondary focus should be what the core does not directly offer and their ability to integrated with 3rd parties through their API.
An API allows credit unions to take advantage of new products and features that are developed outside their core. As technology rapidly develops, new companies are popping up with products that can give your CU a boost in your product offering or operations. Tapping into these products does not and should not require moving to a new core. Your core provider should realize this, and embrace it, by developing the ability to integrate other services to their offering through an API.
A best-in-class core processor should allow you to support your members, protect their data, and allow your CU the ability to grow. It should have a strong central foundation that is stable yet scalable. Once you have partnered with a core processor that provides these benefits, investigate the core's ability to integrate with 3rd parties. A core processor should recognize they can't offer the 'best of breed' in every ancillary product and should allow for simple integration with fintech companies who specialize in niches of the financial services industry.
If you promise a customer a great car with a shiny, new paint job, a nav system, and custom leather interior, they're going to expect it looks comparable under the hood. If its core functions repeatedly fail, that's what they call a lemon. Don't let your potential core provider distract you with all the bells and whistles...Make sure you've got a powerful piece of machinery under the hood. Then be sure their API allows for all the ancillary integrations you want.