Re:What Functional Programmers Get Wrong About Systems
by kortex on Tuesday February 10, 2026 @10:38AM
(#46961203)
Literally the second section:
> Here is the central claim: the unit of correctness in production is not the program. It is the set of deployments.
The thesis essentially boils down to: functional programing paradigm, type systems, strong interfaces, etc, are all fantastic tools for ensuring the correctness of a program, but the system is not a program, and so these tools are necessary but not sufficient to ensure the correctness of a distributed application.
> Here is the central claim: the unit of correctness in production is not the program. It is the set of deployments.
The thesis essentially boils down to: functional programing paradigm, type systems, strong interfaces, etc, are all fantastic tools for ensuring the correctness of a program, but the system is not a program, and so these tools are necessary but not sufficient to ensure the correctness of a distributed application.