Narrow waist

Source The narrow waist (of an hourglass) is a software concept that solves an interoperability problem, avoiding an O(M × N) explosion. All of these are narrow waists:

• Interchange [[format]]s like [[JSON]]
• Networking [[protocol]]s like [[HTTP]]
• Operating system interfaces like [[Win32]] and [[POSIX]]
• Instruction set architectures like [[x86]], and arguably [[WebAssembly]].