A Bayesian networks developer designs and implements probabilistic models known as Bayesian networks. These models represent complex, uncertain systems using nodes and edges to show variables and their dependencies. The developer's job involves understanding the system, defining variables, determining dependencies, and calculating probabilities. They use programming languages and software tools to create these models. They also test the models' predictive accuracy and modify them as needed. Their role requires strong statistical, analytical, and programming skills. They often work in fields such as artificial intelligence, data analysis, healthcare, and robotics, where understanding uncertainty is vital.