In a job interview for a data scientist position, I was asked questions on more IE oriented packages such as CPLEX and GUROBI. Although job description included the usual suspects list of data science software such as R and Python, the company really was looking for someone who could address supply chain optimization problems. There were some questions asked on data mining such as unsupervised learning, clustering, kmeans, the ‘elbow’ method of finding the tentative number of clusters but the need for an optimization expert was discussed much later in the process.
https://www.ibm.com/analytics/cplex-optimizer
https://www.gurobi.com/