Embedded developer here, automotive-related. C, some Python for tests, some shell scripts, CMake, etc. for CI. Review of hardware schematics, reading datasheets, reading various standards documents (USB, various SAE standards, various ISO standards, etc.) is required. Firmware updates take weeks of testing, even though the unit tests run in seconds they can't catch most errors the system can encounter in practice, and simulator tests don't catch things like increased temperature raising power consumption without an expensive thermal chamber. Factory production sets hard deadlines on quite a few things. All together, that means it's a more deliberate, slower release cycle.