An Aspen Plus developer designs, develops, and optimizes chemical processes using Aspen Plus software. They create simulation models of chemical processes, analyze the results, and make necessary adjustments to optimize efficiency, safety, and profitability. They work closely with process engineers and other professionals in the chemical industry to understand process requirements and constraints. They also troubleshoot and resolve issues with the simulation models. Furthermore, they may also conduct training sessions for other engineers on how to use Aspen Plus software, and stay updated with the latest developments in the field of process simulation and modeling.