We are glad to announce the fourth edition of the Complexity72h workshop, which will take place at Palma de Mallorca, Spain, on June 26-30 2023.

Complexity72h is an interdisciplinary workshop for young researchers in complex systems. Participants form teams and carry out projects in a three days' time, i.e. 72 hours. The goal of each team is to upload on the arXiv (or similar repositories) a report of their work by the end of the event. The editions of 2018 and 2019 were a success: 11 out of 11 projects have become arXiv preprints and new collaborations have been born. The 2020 edition was canceled due to the pandemic. But we are now back for a 2023 edition, which will take place in Palma (Mallorca, Spain) on June 26-30.