A configuration file grew over the years to two thousand lines.
A developer asked the senior, “Why are all of these settings here?”
The senior answered, “Each one was once a question someone could not answer.”
“And now?”
“Now they are questions no one remembers asking.”
Unpacking the Teaching
Every line in that file started as a decision made under pressure. Something behaved strangely in staging on a Thursday night. Someone needed a timeout to be longer, a retry count to be higher, a feature to be dark for one customer. Adding a setting made the problem go away, and the reason for the setting went
away with it.
That is what the senior developer means. A configuration flag is a small confession. It says the team was not certain, so they made the behavior adjustable and moved on. Deferring the decision is often the right call in the moment. The cost arrives later, when the uncertainty has resolved and the flag stays behind, still adjustable, still waiting for someone to prove it can be removed.
Read generously, a 2,000 line config file is the most honest documentation a project has. It marks every place the system surprised the people who built it. The trouble is that documentation without dates, names, or reasons stops being documentation and becomes surface area. Each boolean flag doubles the number of
states the system can occupy. Twenty of them, and no test suite you can afford covers the space.
Deletion for its own sake misses the point. Before removing a setting, find out what question it answered. If nobody can say, that silence is information, but it is weaker information than it appears. A safer path is to instrument the file. Log every read that returns a non-default value, wait a quarter, and the dead settings will name themselves. The ones still in use will have earned their place, and you can write down why while someone still remembers.
Before adding the next one, there is a smaller practice available. Write the reason beside the setting, with the date and the incident that caused it. Two sentences. That single habit turns a graveyard into a record, and it costs almost nothing on the day it matters least.
The next time you reach for a new setting, notice what you are doing. Are you giving the system a choice, or avoiding making one?