Research on presidents and presidential institutions has never been out of date. However, presidents in semi-presidential and parliamentary systems have attracted even more attention from scholars in the last decade. Furthermore, presidential institutions, executive-legislative relations and inner-executive relationships between president and government are important topics in most countries' constitutional discourses. Their importance and thus their popularity make presidential institutions and relating questions no less disputed among scholars. Nevertheless, its importance stems largely from the role presidential institutions play in countries' democratic development, the efficiency of governance, but also the simple fascination for presidential leadership. In this article, I will show that, despite the variety of approaches and topics, a common pattern emergesnamely, the shared emphasis by scholars of presidential institutions on the importance of the variety of constitutional design. The aim of this contribution is to review recent scholarship on presidential institutions in semi-presidential and parliamentary democracies, map existing trends, in particular present the common topic of constitutional design, and propose further research directions for a field where the standards are already immensely high.