Warning! They do back channel references. I interviewed with several employees (including the CEO), completed a case study, and gave 3 references. Apparently all of this positive feedback and everyone on the W&B team feeling as if I was a good fit was not enough. They also did a back channel reference and decided not to give an offer based on one comment. Plus, they never even had solid confirmation that this reference worked with me. They just assumed. Back channel references are generally considered in the HR industry as unethical and unprofessional. If back channel references trump a long interview process and positive references, then do that first rather than waste everyone's, (including your CEO), time.