With systemd you can configure WatchdogSec=X parameter if application support NOTIFY_SOCKET (env var).

Example:

#include <systemd/sd-daemon.h>  // link with -lsystemd

uint64_t usec;
if (sd_watchdog_enabled(0, &usec) > 0) {
    // ping at half the interval, from your main loop
    // usec = WatchdogSec in microseconds
}

sd_notify(0, "WATCHDOG=1");

Why can be useful - if application hung, systemd is not able to restart it automatically:

• Deadlocks in the main loop (mutex deadlock, stuck blocking syscall, infinite loop)
• Process frozen on unresponsive I/O (NFS hang, stuck DB call — if that call blocks the pinging loop)
• Event loop starvation