The Neurodata Without Borders: Neurophysiology (NWB:N) Developer Hackathon is a hands-on activity lasting several days in which neurophysiology researchers create solutions using the open source NWB:N software packages. In contrast to conferences and workshops where the primary focus is to report results, the objective of the Hackathon is to provide a venue for NWB developers and creators and users of neurophysiology open-source software to collaboratively work on any related research projects.