A Dutch based psychology firm approached us to upgrade their existing system whereby they profile all employees in a company to ensure the right balance within their workforce.
The system we wrote for them was a sophisticated web-based system written in Django that had the flexibility to both define questionnaires and content pages, as well as to define on-the-fly calculations to process the answers.
The calculations were defined using ad-hoc python functions embedded into the pages, which allowed the creation of data attributes on the fly during rendering of the pages.
The result was a system written over 2 years, that could be used to create any sort of complex website and graphical PDF report, not limited to the psychometric field.
It was particularly challenging to ensure the site speed was acceptable, despite almost every part of the system being configurable. Part of this solution was to pre-process all the pages into dynamically created python files which where cached during before rendering.