21CTO

Mar 13, 2026 · Fundamentals

Tony Hoare: The Genius Behind Quicksort, Null References, and a Billion‑Dollar Error

Tony Hoare, Turing Award laureate and creator of Quicksort, introduced the null reference in 1965—a design later dubbed the “billion‑dollar mistake”—and spent his career advancing programming language theory, concurrency models, and formal verification, while his public apology in 2009 spurred a wave of safer language designs.