The Echelle SPectrograph for Rocky Exoplanets and Stable Spectral Observations (ESPRESSO) is an extremely stable high-resolution spectrograph currently under construction, to be placed at Paranal Observatory in the ESO VLT Combined Coudé Laboratory (CCL). With its groundbreaking characteristics (resolution up to ˜200,000; wavelength range from 380 to 780 nm; centimeter-per-second precision in wavelength calibration) and its very specific science cases (search for terrestrial exoplanets with the radial velocity method; measure of the variation of fundamental constants through observations of QSO spectra), ESPRESSO is aimed to be a real "science machine", an instrument whose data flow subsystems are designed in a fully-integrated way to directly extract scientific results from observations. To this purpose, an end-to-end operations scheme will be properly tackled through tailored observation strategy, observation preparation, data reduction and data analysis tools. The software design has successfully passed the ESO final design review in May 2013 and it is now in development phase. In this paper we present the final design for the ESPRESSO data flow system (DFS) with some insights into the new concepts and algorithms that will be introduced for observation strategy/preparation and data reduction/analysis. Eventually, peculiarities and challenges needed to adapt the ESPRESSO DFS in the pre-existing ESO/VLT DFS framework are outlined.