He studied composition with Zygmunt Krauze at the Academy of Music in Łódź, Mark Andre, and Manos Tzangaris at the High School of Music in Dresden, as well as Yannis Kyriakides at the Royal Conservatoire in The Hague, and at numerous masterclasses. 

His works focus on the phenomenon of touch as a source of sound and a channel of sound perception, as an axis along which the performer-instrument relation is formed, and as a medium of social communication. By applying performative means, multimedia, and tactile references, Krzewiński proposes to his audience new ways of contact with music and with corporeality. 

In 2018 the web portal Culture.pl hailed him as one of the ten most promising composers of the young generation in Poland. His works have been performed and commissioned by ensembles such as Musikfabrik, Garage, Kompopolex, NEMØ, Ensemble Royaal, the Kwiatkowska/Pałosz duo, and others. His compositions and installations have been presented at festivals in Poland, Belgium, the Netherlands, Germany, Portugal, and China. 

Krzewiński is the winner of the Government of Saxony’s award Förderpreis für Junge Komponisten 2019. He has been artist-in-residence at the Binaural Nodar SOCCOS Residency in Vouzela, Portugal (2016), LABO in Antwerp (2017), and PointX with NEMØ Ensemble in Ghent (2018). In 2019 Bôłt Records released the DVD Incorporate, featuring his chamber music. 

With audiovisual artist Aleksandra Chciuk he has created, among others, the concert/installation Black of Granule for two performers, piano and one listener, presented during Musica Privata in Łódź (2016) and the Instalakcje festival in Warsaw (2018), as well as the audio performance Weave-Machine commissioned for the opening of the International Tapestry Triennial at the Central Museum of Textiles in Łódź. 

He has created a series of objects known as Ameublement de Musique, presented so far as an installation and in concert in Poland, Belgium, the Netherlands, and Germany. 

Selected works: Glass Wood Plastic for violin and marimba (2015), I | 0 for six singers, viola and cello (2015), Mille-feuille for dancer and electronics (2015), Contre no. 1 for violin and cello (2016), Black of Granule, installation/concert (with Aleksandra Chciuk, 2016), Edging for flute, clarinet, trombone, percussion, violin, cello, double bass and seven dancers (2016), Another Air for flute, accordion, percussion, electronics and 20 fans (2017), Inside for Musikfabrik with Harry Partch’s instruments and ameublement de musique sound objects (2018), Entrefor bass clarinet, percussion, e-piano, violin, double bass and media (2018), Incorporate for violin, electronics and video (with Aleksandra Chciuk, 2018), Ep for double bass and deaf poet (2018), Weave-Machine, audio performance (with Aleksandra Chciuk, 2019), AdM Room, installation-like piece for two marimbas and ameublement de musique sound objects (2019), Contre no. 2 for two performers and electronics (2019).