> Unit testing imo is pre-LLM. It was mostly to keep the human honest because the human can't possibly read all the code to make sure nothing broke.

What?!

Unit testing was to ensure the code operated according to an intended specification or outcome especially when it deals with a complex support matrix. It extended well beyond the codebase itself! You can have language errors where output behaviors differ between one supported version to another (ex. Java 11 vs Java 17), runtime errors that are specific to operating system quirks (ex. RHEL 8 vs RHEL 9), or workarounds added to your codebase for known bugs in different dependency libraries you support at compile/run time (ex. Net-SNMP 5.2 vs 5.5). It wouldn’t matter if someone read all your code; you would still have the potential for errors caused by the components needed to run your software.

If your project doesn’t have to worry about these types of issues then lucky you and continue on without unit tests for as long as you can.