Sobczak’s second major collaboration with other artists is the performance duo Polen Performance founded with Justina Los in 2015. Their performances primarily addressed issues of Polish-German identity and the role of the artist. The duo was characterised by white work overalls. In addition to public places, they also used virtual space. In 2016, they launched a performance on Snapchat – Snapformance – and took advantage of the ephemeral nature of the app, which retains content for only 24 hours. One of their most important performance actions was Deutschlandtransport (2016), which took place on the 35th anniversary of Joseph Beuys’s Polentransport action. In 1981, Beuys travelled from Düsseldorf to the Łódź Art Museum in order to donate a crate of more than a thousand works to it. In their perverse response to this action, Sobczak and Los enclosed themselves in a crate along with an archive of their works and embarked on a reverse trip to the Museum Kunstpalast in Düsseldorf. Other major performance actions by the duo included How to Behave During a Terrorist Attack, Artloop Festival, Sopot 2016; Thank You for the Performance!, Festiwal Sztuki Efemerycznej ‘Konteksty’ (Konteksty Festival of Ephemeral Art), Sokołowsko 2016; Usługi wernisażowe (Vernissage Services), CCA Ujazdowski Castle, Warsaw 2016; Polen Performance Paranormal, lokal_30, Warsaw 2015; Performance, Welcome to Polen!, Poligon, Warsaw, 2015; Usługi Performerskie (Performer Services), WRO Media Art Biennale, Wrocław 2015.
Joseph Beuys executed the Polentransport action in 1981, during which he travelled from Düsseldorf to the Museum of Art in Łódź, bringing a trunk of his work as a gift. On the 35th anniversary of this famous activity, the artistic duet Polen Performance (Justina Los and Mikołaj Sobczak) took off on the reverse journey in order to pass on the archive of their creativity to the collection of the Museum Kunstpalast in Düsseldorf. With this gesture, the creators closed the time of their sojourn in Poland.