Our customers develop online questionnaires. Most of those are stock controls which don't require any logic, like asking a question about the user's about age.

Our customers develop online questionnaires. Most of those are stock controls which don't require any logic, like asking a question about the user's about age. Sometimes you need simple or complex control logic, e.g. display these additional questions only to users that meet certain criteria, like 18-25 Males who know at least 3 out of 7 competing products. The casual users might select that from a GUI, the more expert might enter the Python code directly. The complex control logic might be: plug in the responses to those questions into giant matrix with thousands of coefficients to segment users into groups. It can get even more extreme; we even had one user who wanted to use a 200,000-line C function to determine this segmentation, apparently that was some neural network output from a program called "Salford Predictive Miner".