This paper outlines the architecture of the ARISTON expert system shell for vocational counselling. The information system prompts the user to answer a series of psychometric questions, for a period of approximately 40 minutes. The system then analyses the answers and creates a report automatically and sends this to the e-mail address of the user, with no human intervention. The report contains analytical conclusions regarding the personality of the individual, the motives behind choosing a career, aptitudes–abilities, and a list of approximately 30 professions / specialisations that match with the personality traits of the user. Herein, we show that expert human knowledge can be codified to support advanced vocational counselling tasks in an integrated manner, quantifying precisely personality traits, aptitudes, abilities, motivation, and preferences.