Error correction code (ECC) coding for key-value data storage devices. In one embodiment, a controller includes a memory interface configured to interface with a memory; an ECC engine configured to perform ECC coding on data stored in memory; a controller memory including a flash translation layer and a namespace database; and an electronic processor. The electronic processor is configured to receive data to be stored, separate the data into a plurality of sub-code blocks, and allocate parity bits to each sub-code block of the plurality of sub-code blocks.