These excerpts below from Richard T. Gray’s A Franz Kafka Encyclopaedia. I’ve omitted the introductory parts about Freud and Marx’s influence on Kafka’s writings, as they do not require elucidation. I am interested in this idea that Kafka’s work could be located at the interstice of modernism and postmodernism.

[Finally], Kafka’s persistently self-reflexive questioning of the unstable role of the figurative language to metaphysical truth can be understood in light of Nietzsche’s theory of accepted truths as the ideological sedimentation of language whose metaphoric construction has been forgotten. Other modernist features are Kafka’s awareness of linguistic signification, his doubts about the mimetic ability of literary language to adequately reflect external reality, and his concept of art as a mere approximation, rather than a symbolic expression, of truth, essence, and other categories of traditional aesthetics. Kafka’s ironic disfiguration of the canonical icons of classical-humanistic education, such as Greek mythology, biblical parables, and classics of world literature, can also be related to the modernist critique of cultural tradition.

[…]

Others suggest that [Kafka] is a precursor of postmodernism. Among these features are his fascination with simulacra and facades, his preference for the playfulness of linguistic signification and the nonclosure of meaning, his sense of decenteredness and instability of human subjectivity, and his self-reflexive depiction of reality as a construct of language games, power relations, and cultural myths, rather than as a preexisting divine or social world. Thus the seemingly ahistorical nature of Kafka’s writings, often claimed to have a unique status in literary history, can be located at the intersection of classical modernism and the as yet incomplete project of postmodernity.