[aidenn0]

RE: Automated testing.

Modulo certain forms of static analysis, your code is ultimately only as good as it is well tested[1]. Non-automated tests do count here, but for long-maintained codebases the cost of automating pays for itself very quickly.

1: Note that pretty much all code has been informally integration tested (A "can I run it" type of smoke-test is a very simple integration test). Similarly all compiled languages (and any interpreted languages that parse an entire file before running code) has some static analysis, as syntax errors will be caught. Unless you check in code without compiling or running it, you are already doing some testing.