A coding practice that enhances software maintainability and scalability is modular programming. This approach involves breaking down a program into smaller, manageable components or modules that each handle specific functionalities. Modular code promotes reusability, as developers can easily interchange or update modules without affecting the entire system. Additionally, this separation of concerns improves collaboration among developers, making it easier to work on different features simultaneously. Overall, modular programming leads to cleaner code, reduced complexity, and more efficient development processes, ensuring long-term software viability.