By Vivek Sharma·4 MIN
Little's Law: The One Equation Every Engineer Should Know
Little's Law is a result from queueing theory, a branch of applied mathematics, and it fits in one line: L = λ × W. The average number of items in a system (L) equals the average rate at which they arrive (λ) multiplied by the average time each one spends inside (W). The system can be a checkout line, a thread pool, a message queue or a whole microservice. The law does not care.