He published several essays and reviews about the works of Hans Henny Jahnn and Franz Kafka,[3] in various journals and anthologies, such as in the Neue Rundschau and in Revista de Libros, Madrid.

While Kafka had a relatively small literary output, his influence is so immense that Stach estimates there are at least 130,000 web sites devoted to him.

[4] Stach divided his biography of Kafka into three volumes: from birth to age 27 (1910), the period when he wrote his most famous works (1910–1915), and everything thereafter (1916–1924).

However, obtaining enough suitable research material for the period covering early family, childhood, adolescence, and early adulthood (1883–1910), relies in part on obtaining access to the estate of Max Brod in Tel Aviv, which has so far largely been inaccessible to research due to legal issues.

[7] In 2008 he won a Special prize of the Heimito von Doderer-Literaturpreis for his biography Kafka – Die Jahre der Erkenntnis.