Why I Read Other People's Config Files for Fun
When I join a new codebase — a new team, a new company, the acquired system nobody explains properly — I don’t start with the README, and I don’t start with the code.
I start with the config files. All of them, settled in properly, read cover to cover like memoirs. Colleagues find this eccentric until they watch what I come back knowing, so let me make the case, because it rests on a distinction I’d defend anywhere:
The README is what a team wants to believe. The code is what they built. The config is what actually happened to them.
Documentation is aspiration — I’ve written love letters to it, and love letters are exactly what it is. Code is intention, executed. But config — config is experience. Every value in a mature config file is the sediment of a real event: nobody writes `retry_limit: 7` from first principles.
Nobody sits in a design review and derives seven. Seven is a settlement — the peace treaty at the end of some war nobody documented: five wasn’t enough (an incident), ten hammered a struggling downstream (another incident), and seven is where the fighting stopped. The number is the treaty.
The war is invisible.
And a whole config file is
And a whole config file is a stack of such treaties, which is why reading one is reading the system’s unauthorized autobiography — the one the README would never approve for publication.
Specimens from the collection
A tour of my favorite finds, all real, details filed off:
`max_connections: 199`. Not 200. One hundred and ninety-nine. Somewhere, someone knows exactly why — a vendor limit of 200 with one connection reserved for something, a monitoring probe, an escape hatch, a superstition that earned tenure.
The off-by-one from a round number is the most information-dense signal in any config: round numbers are guesses; unround numbers are scars.
I found the person eventually. The reserved connection was for the debugger, “after the day we couldn’t get in.” What day? “The day.”
Enough said, apparently, forever.
`TEMP_FIX_DO_NOT_USE`. An environment variable bearing this name, set in production, load-actively — actively consumed by two services, since 2019. Every word of the name is a fossil of intent: temporary (it wasn’t), fix (it was), do not use (they did).
It’s the flag biography I’ve written, compressed into a single shrieking identifier that everyone has scrolled past for six years. The name is doing its best.
Names always are.
The commented-out block with no explanation
The commented-out block with no explanation. Config’s ghost limbs — twelve lines of dead settings, preserved, unexplained, too frightening to delete. (Is it history? Is it the rollback plan? Is it coming back? Nobody knows. It survives every cleanup like a family photo of someone no one can identify.)
And the aristocrat of the genre: the production override file that’s longer than the defaults.
Sit with that shape when you find it — and you will find it — because it’s an entire organizational confession in a directory listing: when the exceptions outweigh the rules, the exceptions are the rules, and the defaults are a founding myth the system tells about itself.
That file is the gap between the company’s self-image and its Tuesday, measured in lines.
The species and the individual
Here’s the deeper reason config reads so true, and it’s the frame I’d offer any engineer inheriting anything:
Get Jiteshkumawatjpr’s stories in your inbox
Join Medium for free to get updates from this writer.
Design documents describe the species. Config describes the individual. The architecture doc tells you what this kind of system is meant to be — the platonic deployment, the diagram animal.
The config tells you about this particular animal: every dent from every road it actually drove, every climate it actually survived. Timeouts stretched for the one slow partner. Pools sized for the traffic that actually came, not the traffic the capacity plan predicted.
Retries tuned by grief.
You can reconstruct a system’s entire
You can reconstruct a system’s entire case history from its overrides the way a vet reads a rescue animal — here’s where something bit it, here’s what it learned to flinch from — and the reconstruction is reliable, because config, unlike prose, was never written to impress anyone.
Nobody performs in a YAML file.
It’s the one text in the whole repository with no audience in mind, which is precisely why it’s the one that never lies.
Sanjay — platform, previously on record about migrating promises — reviews infrastructure for a living and put the whole practice in one line:
I’ve tested him on it. He goes about eight for ten, and the two misses were incidents so old the treaty had been renegotiated.
Signing the treaties
The workflow ending, because the format demands it and this one’s cheap:
On my team, every config override
On my team, every config override now carries its war — one comment line: date, incident link (or the word “superstition,” which is allowed, and honest), and a removal condition.
The same doctrine I’ve applied to comments and flags and letters, arriving at last at its truest home: the truth was always going to live in the config.
We just started signing it.
The next reader — some future me, some acquired stranger, some archaeologist with my habits — will read `retry_limit: 7 # 2026–03, INC-4412, revisit if downstream v2 ships` and know the war, the treaty, and the terms of peace, in one line.
And on day one of anything new, you’ll still find me where the truth lives: settled in with the overrides, reading the scars, counting the unround numbers —
learning what actually happened to these people,
in the only file where they never once thought to pose.
I write about what building software actually feels like. Open your production overrides tonight and find your unroundest number. There’s a war in it. Comments open — bring your 199s.
