It depends on what you mean by "formal methods". Fully verifying code is fully correct is extremely expensive. Partially verifying code is somewhat correct is a

It depends on what you mean by "formal methods". Fully verifying code is fully correct is extremely expensive. Partially verifying code is somewhat correct is a lot less expensive. Verifying the _design_ you intend to code is less expensive than that, and is actually pretty economical. I wrote about this in-depth here: https://www.hillelwayne.com/post/why-dont-people-use-formal-methods/ https://www.hillelwayne.com/post/why-dont-people-use-formal-...