Carmack's programming style is characterized by a relentless pursuit of optimization and efficiency. He prioritizes speed and performance, often using assembly language to fine-tune critical sections of code.

Carmack pioneers several groundbreaking graphics techniques, including raycasting, binary space partitioning (BSP), and surface caching. These techniques enable the creation of fast and immersive 3D environments in games like Wolfenstein 3D, Doom, and Quake.

Carmack is a strong advocate for open-source software. He releases the source code for several of id Software's game engines, including Doom and Quake, allowing other developers to learn from and build upon his work. This contributes significantly to the advancement of game development technology.

Carmack demonstrates a continuous commitment to learning and adapting to new technologies. He actively explores new programming languages, graphics APIs, and hardware platforms, constantly seeking ways to improve his code and push the boundaries of what is possible.

While known for his low-level optimization, Carmack also adopts modern programming practices, including unit testing, code reviews, and agile development methodologies. This allows him to maintain code quality and collaborate effectively with other developers.