The robustness of Linux is widely acknowledged, but it can’t quite match the microsecond management of a real-time operating system (RTOS) for time critical situations such as CNC machine instructions, vehicular control, or health sensor collection. If your software must record, manage, or control events within a narrow and precise time window and you’re invested in Linux for core development, you can consider some of these strategies for handling time-critical tasks without abandoning your familiar environment.
If you’re working on something that truly needs faster response times at the kernel, you might be better off looking at Zephyr or FreeRTOS for more consistency. “Real-time” mode in the plain Linux sense is just a series of patches which work towards one goal (skipping schedulers and such), but not all coherently working together. Other RTOS’s out there are designed from the outset to streamline such things.