Depends on what it is. LLMs are not a magic security solution
First, you ignore most of the non-security critical code. A cron task sending reminders is unlikely to have anything exploitable.
Second, security by design: You can make the design so that a security issue cannot easily exist (or have any impact)
And third, after all that, if the code is highly security-sensitive, you can run it through an LLM. Which I do, sometimes.
For example, I run it on my payment processing code for my relay. But even then, the worst exploit would be faking a payment (as it is written in a memory safe language) and there is spam for 2 hours and then I ban the account.
The easiest solution to security problems is to make sure they can’t impact you in the first place even if something does happen
