He spent the first ten years of his professional career at Schöner Wohnen, where he created photo spreads and proselytized to readers on practical design. Near the coda of this editorial work, Maly began to freelance design; among his first proposals were his Serie 1 collection of living room items for Tecta (1967) and his Trinom seating family for Cor (1959). 

In 1970, Maly founded his eponymous design studio in Hamburg, focusing his efforts primarily toward living room and bedroom furniture. Among his first clients was German manufacturer Interlübke, for whom he proposed his Mutaro Chest of Drawers with leather handles (1979) as part of a firm-wide competition. The winning entry, Mutaro sold prolifically for Interlübke. Maly further contributed to the brand’s catalogue with the textile collections Melange (1983) and Graphis (1984), alongside the commercially-successful cabinet system Duo (1983). 

Around the same time, Maly began design work for Ligne Roset. His debut Peter Maly Bed (1983)—a Ligne Roset bestseller that’s still produced today—endures as an exemplar of Maly’s signature: a blend of Bauhaus geometry with the pared-down functionalism of his Danish modernist heroes, Arne Jacobsen, Hans J. Wegner, and Verner Panton. Into the 1980s, Maly continued to swell out his Ligne Roset oeuvre in this timelessly modern vein; a particular standout includes his modular Prao Sofa (1985), which features armrests and a back that can be removed and adjusted. 

Maly has remained active in the 21st century, designing collections and stand-alone pieces for Anta, Behr, JAB Ansteoetz, Poliform, Mauser, Thonet, and Tonon, among others. Of late, Maly has collaborated with Japanese manufacturer Conde House. This ongoing work includes his Tosai seating collection (2007) and Hakama Table (2012), which sleekly combine Maly’s European functionalism with traditional Japanese craftsmanship and material.

Maly has been recognized with a number of awards, including the Federal Prize for Good Form in 1985, the Du Pont International Award in 1986, and the Grand Prix de la Critique in Paris in 1989.