Senior engineers at Google and Meta read the same code you do — they just see one more layer: memory. This is that layer, X-rayed with C in under 7 minutes. Three things hiding under every variable you write — and the one compiler flag that shows you all of them. What you'll see: • Why a struct with one char and one int is 8 bytes, not 5 (padding alignment) • Why 12 MB crashes when 1 GB runs fine (stack vs heap, the 8 MB ceiling) • The bug that passes 100 tests then crashes on Friday (dangling r