Ah, the classic bitwise vs modulo showdown. Left guy uses (num%2) == 0 to check if a number is even - the textbook approach they teach you in CS101. Right guy with the sunglasses? He's using (num&1) == 0 - the bitwise AND operation that's marginally faster because it works directly with the bits. Same result, but the bitwise operation skips the division calculation. It's the programming equivalent of bringing a switchblade to a butter knife fight. Technically more efficient, practically irrelevant for most applications, but absolutely essential for establishing your dominance in code reviews.