We were a media company so our CMS was our core technology. We wanted to do some interesting things with built-in analytics and automatic a/b testing which would have required extensive plugins and modifications to WordPress (our primary alternative). It also seemed unlikely that we would be able to find very many good developers (the kind we'd need to build some of the analytics technologies we were considering) who were enthusiastic about developing on WordPress.

In retrospect, it was probably the wrong call. While we made created some unique products and technology that I'm still proud of, it was challenging to get writers on board with some of the newer things (like automatic A/B testing of headlines). It was very expensive to build and maintain a technology team and ultimately without editorial buy-in the returns just weren't there (though our marketer loved it).

My last move before leaving the startup was to transition everything to WordPress.