Since 2019, Justus has been editor-in-chief of CORRECTIV together with Olaya Argüeso. In addition to investigative research on the secret channels of lobbying or illegal party donations, he continues to develop the idea of citizen research.
With the project "Wem gehört Hamburg" (Who owns Hamburg), he and a team launched a research project in 2017 in which several thousand citizens participated. With media partners in various cities, and the help of citizens, CORRECTIV shed light on the non-transparent real estate market. The "Who owns the city?" project, which ran in eight cities, sparked debates about the housing market and is an important signal to continue developing formats for citizen research. Among other things, "Wem gehört Hamburg" was awarded the Grimme Online Award 2019.
In 2018-2019, Justus built the network for collaborative local journalism, CORRECTIV.Lokal. In the network, local journalists and the CORRECTIV team work together on research that exposes local grievances while having national relevance.
In 2021, he was named "Editor-in-Chief of the Year" by Medium magazine, together with Olaya Argüeso.
