Commercial software engineering under the digital economy concept

The counterparties’ economic relations have been mainly transferred to the online sector. This reflects the concept of digital interaction between manufacturers, intermediaries and consumers. At the software engineering stage, it is necessary to use one of the main formalisms - sales funnel, which has transformed into a conversion funnel under the concept of a digital economy. In the presented article, a mathematical model is developed that formalizes in detail all the stages of commercial interaction. The research results provide a set of software engineering algorithms for the expert systems designed for commercial services managers.