A maintainer is responsible for the inspection, maintenance, and repair of various types of equipment or components. Your job duties as a maintainer depend on the industry in which you work. For example, in manufacturing, your responsibilities include troubleshooting, repairing, modifying, and programming computer numerical control (CNC) machinery, such as punch presses. In the railroad industry, you can work as a signal maintainer and service the electrical components on railway tracks. Another maintainer job is in the software industry, in which your responsibilities include troubleshooting issues, writing code and documentation, testing solutions, and reviewing pull requests from other developers.