The diversity of extrasolar planets discovered over the past three decades continues to challenge our understanding of the physical processes that drive the formation of planetary systems. With more than 4300 exoplanets discovered to date, the exoplanet sample has grown sufficiently large to enable statistical studies of these objects and estimate occurrence rates. The vast majority of these discoveries came from the Kepler space mission, which relied on the transit method. However, the Kepler planets have orbital periods well below 100 days, so the sample is strongly biased to close-in companions. It is evident that small, rocky planets are much harder to detect than gas giants, as are planets in wider orbits. I will give an overview of the methods we have at our disposal to detect exoplanets, with a particular emphasis on microlensing, and describe the challenges still facing us. I will conclude by outlining the main areas of future research in the field of exoplanet science.