What is the impact of Struct Padding and Memory Alignment?

Go pads structs to align memory addresses for faster CPU access, which can waste memory if fields are ordered poorly.

CPUs read memory in word-sized chunks (e.g., 8 bytes on a 64-bit system). If an int8 (1 byte) is followed by an int64 (8 bytes), Go adds 7 bytes of invisible padding so the int64 starts on a clean 8-byte boundary. Sorting struct fields from largest to smallest minimizes padding and shrinks the overall struct size.