Why Your Codebase Is Unmaintainable (And How to Actually Fix It)

Ever inherited a codebase where a variable named x2 controls whether the billing system charges customers? Or opened a 3,000-line function and immediately closed your laptop?

You're not alone. Back in 1999, Roedy Green wrote a satirical essay called "How To Write Unmaintainable Code" — a tongue-in-cheek guide to ensuring job security by making your code impossible for anyone else to understand. It recently resurfaced on Reddit, and reading it in 2026 is equal parts hilarious and painful. Painful because most of us have seen every single one of these anti-patterns in production code. Some of us have written them.

Let's take the most common unmaintainable code patterns, understand why they actually cause damage, and walk through concrete fixes.

The Root Cause: Code Written for Computers, Not Humans

Here's the thing people miss — unmaintainable code usually works. It compiles. It passes tests (if tests exist). The problem isn't correctness; it's communication. Code gets read 10x more than it gets written, and unmaintainable code treats future readers as an afterthought.

Green's essay identifies dozens of sabotage techniques, but they cluster into a few core problems:

• Naming that obscures intent
• Structure that hides logic flow
• Coupling that makes changes terrifying
• Missing context that forces archaeology

Let's fix each one.

Problem 1: Cryptic Naming

Green's essay suggests naming variables after your pets or using single letters everywhere. Funny on paper. Less funny when you're debugging at 2 AM.

# The unmaintainable version
def proc(d, t, x):
    r = d * t
    if x:
        r = r * 0.85  # what is 0.85? why? who decided this?
    return r

# The fixed version
def calculate_invoice_total(daily_rate, days_worked, has_volume_discount):
    total = daily_rate * days_worked
    if has_volume_discount:
        VOLUME_DISCOUNT_MULTIPLIER = 0.85  # 15% discount per contract term §4.2
        total = total * VOLUME_DISCOUNT_MULTIPLIER
    return total

The fix isn't just "use longer names." It's about encoding intent and business context into the name. has_volume_discount tells me this is a business rule. x tells me nothing.

Problem 2: Functions That Do Everything

Green recommends writing functions with "creative side effects." I've seen this in the wild — a function called validateEmail() that also updates the user's last-login timestamp, sends an analytics event, and occasionally writes to a cache.

// The unmaintainable version — validateUser does way too much
function validateUser(user) {
  if (!user.email.includes('@')) return false;
  user.lastSeen = Date.now();          // surprise side effect
  db.updateLoginCount(user.id);         // another surprise
  analytics.track('validation', user);  // why is this here?
  return true;
}

// The fixed version — each function has one job
function isValidEmail(email) {
  return email.includes('@') && email.includes('.');
}

function recordUserActivity(userId) {
  db.updateLastSeen(userId, Date.now());
  db.incrementLoginCount(userId);
}

function trackEvent(eventName, metadata) {
  analytics.track(eventName, metadata);
}

The single-responsibility fix is well-known, but people still skip it because splitting functions feels like "extra work." It's not extra work. It's the work. A function with side effects is a landmine. Every caller has to know the hidden behavior, and new developers never will.

Problem 3: Magic Numbers and Buried Configuration

Green's essay jokes about scattering literal numbers throughout the code with no explanation. I ran into this exact problem last month — a codebase with if (retries > 7) in four different files, each with a slightly different number.

// The unmaintainable version
func shouldRetry(attempts int, statusCode int) bool {
    return attempts < 7 && statusCode != 429 && statusCode != 503
}

// The fixed version
const (
    MaxRetryAttempts    = 5
    StatusTooManyReqs   = 429  // HTTP 429 - rate limited
    StatusUnavailable   = 503  // HTTP 503 - service down, retry is pointless
)

// nonRetryableStatuses defines HTTP codes where retrying won't help
var nonRetryableStatuses = map[int]bool{
    StatusTooManyReqs: true,
    StatusUnavailable: true,
}

func shouldRetry(attempts int, statusCode int) bool {
    return attempts < MaxRetryAttempts && !nonRetryableStatuses[statusCode]
}

Constants aren't glamorous, but they're the difference between "I can safely change this" and "I have no idea what breaks if I touch this number."

Problem 4: Comments That Lie (or Don't Exist)

The essay suggests writing comments that contradict the code. That's the evil version. The common version is comments that were accurate two years ago but nobody updated them after the refactor.

// The unmaintainable version
// Process the transaction and send email notification
public void processTransaction(Order order) {
    // This hasn't sent emails since 2024.
    // It now updates inventory AND triggers a webhook.
    inventoryService.decrementStock(order.getItems());
    webhookService.notify("order.processed", order);
}

My approach: delete comments that describe what the code does (the code already says that) and only keep comments that explain why. The "why" is the part that isn't obvious from reading the code.

// Webhook must fire BEFORE payment capture — downstream fraud
// detection depends on seeing the order event first (see incident #1247)
public void processTransaction(Order order) {
    webhookService.notify("order.processed", order);
    paymentService.capturePayment(order.getPaymentId());
}

That comment earns its place. It prevents someone from reordering those lines and causing a production incident.

Prevention: Stop Unmaintainability at the Door

Finding and fixing these patterns in an existing codebase is reactive. Here's how to prevent them:

• Linting rules for naming conventions. Tools like ESLint, Pylint, and Checkstyle can enforce minimum name lengths and flag single-letter variables outside of loop iterators.
• Cyclomatic complexity limits. Most linters can warn when a function exceeds a complexity threshold. I keep mine at 10 — if a function needs more branches than that, it's doing too much.
• Code review checklists. Not everything can be automated. "Can a new team member understand this without asking the author?" is a question a human needs to answer.
• The "hit by a bus" test. Morbid but effective. If the author left tomorrow, could someone else modify this code confidently within an hour? If not, it needs work.
• Refactoring budgets. Dedicate 10-20% of sprint capacity to cleaning up tech debt. Not as a special initiative — as a permanent line item. The codebase decays by default; maintenance has to be intentional.

The Real Joke in Green's Essay

The funniest thing about "How To Write Unmaintainable Code" isn't the absurd suggestions. It's that developers have been nodding along for 27 years because they recognize every single pattern. The essay hasn't aged because the problems haven't changed.

Writing maintainable code isn't about following rules. It's about empathy. The next person reading your code might be a junior developer, a contractor with zero context, or you six months from now having forgotten everything. Write for that person.

Or don't. Job security is nice too, I guess.