For his most formative years, Dan Riordan thought his passions would lead him to work with computers and circuit systems. He even obtained his college degree in electrical engineering before realizing that it was human systems he wanted to optimize. After serving in senior management and leadership positions across marketing, sales, operations, international expansion, and more, Riordan has landed as President and COO of ThinkHR. ThinkHR offers knowledge and consultation for human resources scenarios, so Riordan has been at the fore of handling complex people problems. His book Signals: How Questioning Assumptions Produces Smarter Decisions posits a simple reconsideration of our daily decision-making processes, inspired by his favorite concept from engineering school—thermodynamics and the study of energy.