Yes, in many European countries dependents and marital status changes are registered in a national civil registry, which the tax authority can query directly.
Countries like the U.S., Canada, the U.K. cannot easily do that without huge data-sharing reforms.
I am a software engineer with a masters degree in math with a good knowledge of various systems concepts (CPU architecture, multithreading, OS, memory management, optimization). I enjoy working an software problems that challenge me to write mathematicalyl sophisticated code that respects the reality of executing that code on a physical machine.