An apparatus to facilitate scalable runtime validation for on-device design rule checks is disclosed. The apparatus includes a memory to store a contention set, multiplexers, and a validator. In one implementation, the validator is to: receive design rule information for the multiplexers, the design rule information referencing the contention set, wherein the contention set identifies a determined harmful bitstream configuration for each multiplexer instance of the multiplexers, and wherein the contention set comprises a mapping of contents of a user bitstream to configuration bits of the multiplexers; receive, at the validator of the apparatus, the user bitstream for programming the multiplexers of the apparatus; analyze, at the validator using the design rule information, the user bitstream against the contention set at a programming time of the apparatus; and provide an error indication responsive to identifying a match between the user bitstream and the contention set.