Or provide unit test for said log parser and require (or don't) all tests to pass pre-commit. A JSON struct isn't going to stop your colleague from removing nor

Or provide unit test for said log parser and require (or don't) all tests to pass pre-commit. A JSON struct isn't going to stop your colleague from removing nor renaming a field. Removing the logging all together. Or changing the format himself, if your company is really setup for allowing colleagues to so easily break your code -- not that anyone's perfect.