Check out this episode of the #1 people analytics podcast with special guest, Ludek Stehlik, People Data Science Expert at Sanofi!

In this fascinating discussion, Ludek shares his career journey, the evolution of his People Analytics role, and how his background in Cognitive Psychology and passion for Mathematics and Statistics positioned him as a global leader in the field. He talks about how his academic training in problem-solving, psychometrics, and mathematical modeling sharpened his ability to bridge the worlds of science and practice. Ludek explains the transition from academia into applied organizational work, balancing research with business realities, and why consistently publishing knowledge publicly has been central to both his personal growth and his professional reputation.

Ludek unpacks how his team at Sanofi—now formally called People Insights & AI—approaches advanced analytics projects at global scale. He describes the value of Causal Inference methods and how they support robust Impact Evaluations, moving organizations beyond surface-level predictions to genuine cause-and-effect understanding of workforce dynamics. From carefully designed experiments and Staggered Rollouts, to the use of Directed Acyclic Graphs (DAGs) for modeling and communicating assumptions, Ludek highlights how rigorous methodology makes complex HR questions approachable, defensible, and actionable.

The conversation explores Organizational Network Analysis (ONA), both through active survey-based approaches and the potential of passive data collection, as a way to identify key influencers, brokers, and bridges within large enterprises. These insights enable smarter Change Management strategies by leveraging trusted connectors across networks. Ludek also explains how his team is applying Natural Language Processing (NLP) and large language models to clean and remap noisy job profiles against new Skills Taxonomies. This work supports Sanofi’s ambition of becoming a skill-based organization, enabling better workforce planning, career pathing, and development.

Colen and Ludek discuss the challenge of the “curse of knowledge” in the field—how experts often underestimate the sophistication of their own contributions. Ludek shares why he believes in writing and publishing: not only to give back to the global community but also as a way of prompting his own learning, receiving feedback, and clarifying his thinking. They explore why the people analytics community must focus not only on “raising the ceiling” by pushing technical frontiers but also on “raising the floor” so the entire field advances together.

Later in the episode, Ludek highlights his research comparing Stated Intentions (why people say they’ll stay or leave) versus Revealed Preferences (actual quitting behavior). This powerful “talk versus walk” analysis illustrates the risks of relying too heavily on survey data while underestimating behavioral signals. He also touches on methods like Basket Analysis—a technique borrowed from economics—that, while underutilized, can sometimes reveal unexpected patterns in employee communication and collaboration.

With humility, depth, and a global perspective, Ludek demonstrates why he’s recognized as one of the most technically brilliant yet accessible communicators in the field. Whether you’re a practitioner eager to sharpen your skills, an academic looking for applied examples, or a leader seeking the next frontier in workforce intelligence, this episode is packed with actionable insights, advanced methodologies, and genuine inspiration.

If you like this episode, you’d also love exploring prior episodes—visit colenapper.com for the full archive and show links.