Planets form in gaseous protoplanetary disks surrounding newborn stars. As such, the most direct way to learn how they form from observations, is to observe them forming in disks. In the past, this was difficult due to a lack of observational capabilities, and planet formation was a subject of theoretical research. Now, thanks to a fleet of new instruments with unprecedented resolving power that have come online in the past decade, we have started to unveil features in resolved images of protoplanetary disks, such as gaps and spiral arms, that are likely associated with embedded (unseen) planets. By comparing observations with theoretical models of planet-disk interactions, the properties of still forming planets may be constrained. Such planets help us test planet formation models. I will introduce the current status of this field, and highlight some of the latest developments.