It happens at compile time in Julia (required for the multiple dispatch to work), the compile time is just interlocked between runtime steps. Calling something

It happens at compile time in Julia (required for the multiple dispatch to work), the compile time is just interlocked between runtime steps. Calling something with incorrect arguments will fail even if the function is never called during runtime (unless the compiler figures that out using only compile time information and decides not to compile it). But I understand your point, it's not really like a static language checking as it can't do without running the program, so it's better than fully interpreted (a unit test would catch errors even in paths it didn't take) but worse than static checking (as it can't compile 100% of the valid program at once).