Architecture of compact multi-planet systems hosting small-size planets orbiting inner to short-period gas giants (P ≲ 10 d). Each row represents one planetary system (y-axis) and the planetary orbital periods (x-axis). The sizes of the dots correspond to the planet masses, and the colours of the points to the equilibrium temperatures (see colour bar to the right). From top to bottom, the systems are sorted in ascending order of the period of the giant. Shaded dots represent the next three systems with gas giants on Ρ < 25 d orbits. Dots with a vertical line represent planets whose mass is multiplied by sin(i). The semi-circular dots filled with a star shape indicate the host stars; these are colour-coded by age (see colour bar at the top), while their sizes encode their radii.