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Disposable Code vs Durable Code

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Software Is Splitting in Two

Over the last few years, something subtle but important has been happening in software development.

Not a new framework.
Not a new language.
Not even AI — at least not directly.

Software itself is quietly splitting into two fundamentally different categories:

  • Disposable code
  • Durable code

They may look identical in a repository.
They may even be written in the same language.

But they exist for very different reasons, are built with very different assumptions, and require very different engineering cultures.

Understanding the difference matters — because durable code runs the world, while disposable code increasingly surrounds it.

Disposable Code

Disposable code is written to solve a problem right now.

It is:

  • Fast to write
  • Cheap to replace
  • Expected to change or be deleted
  • Optimized for speed of delivery rather than longevity

Typical examples include:

  • Prototypes and MVPs
  • Landing pages and marketing sites
  • Internal tools
  • One-off scripts
  • Experiments and feature spikes
  • Temporary integrations
  • Automation glue

Disposable code is not bad code.

It is often exactly the right code — as long as everyone understands what it is.

Durable Code

Durable code is written to keep working for a long time.

It is:

  • Designed for stability
  • Changed cautiously
  • Extended more often than rewritten
  • Built on boring, proven concepts
  • Maintained by multiple generations of developers

Examples of durable code include:

  • Payment systems
  • Banking and financial infrastructure
  • Logistics and supply chains
  • Healthcare systems
  • Identity and authentication platforms
  • ERP systems
  • Core business logic
  • Operating systems
  • Databases
  • Infrastructure tooling

This is the software that:

  • Moves money
  • Stores identity
  • Routes goods
  • Keeps companies operational
  • Keeps society functioning

Durable code runs the world.

And when it fails, the cost is very real.

The Real Difference: Change Velocity

The most important difference between disposable and durable code is how change is applied.

Disposable Code Changes Fast

  • Rewrites are acceptable
  • Breaking things is survivable
  • Failure is expected
  • Learning is the primary goal

Durable Code Changes Slowly

  • Backwards compatibility matters
  • Risk is carefully managed
  • Changes are incremental
  • Stability is more valuable than novelty

Durable systems evolve through small, consistent changes to what is already known to be stable.

Not through big rewrites.
Not through constant reinvention.
Not through chasing trends.

Why Durable Code Avoids Big Rewrites

Large rewrites are seductive.

They promise:

  • Cleaner architecture
  • Modern tooling
  • Fewer compromises

They also:

  • Erase institutional knowledge
  • Reintroduce old bugs
  • Miss edge cases accumulated over years
  • Create long periods of instability

Most systems labeled “legacy” are not bad because they are old.

They are old because they survived reality.

Durable code accumulates value through:

  • Real-world usage
  • Edge cases
  • Operational experience
  • Hard-earned stability

Throwing that away is rarely progress.

AI and the Explosion of Disposable Code

This is where AI enters the picture.

AI has dramatically lowered the cost of writing code, especially disposable code.

And when the cost drops, volume explodes.

AI excels at:

  • Generating boilerplate
  • Spinning up prototypes
  • Writing CRUD applications
  • Creating integrations
  • Producing scaffolding quickly
  • Translating ideas into working code

The result is:

  • An explosion of MVPs
  • Faster experimentation
  • More short-lived software
  • Entire businesses built around disposable systems

Much of this software is intentionally disposable.

And that is not a problem.

It is a feature.

AI Is a Force Multiplier for Disposable Code — Not Durable Code

AI thrives where:

  • Requirements are fuzzy
  • Failure is cheap
  • Replacement is easy
  • Speed matters more than precision

That makes it perfect for disposable code.

Durable code is different.

Durable systems require:

  • Deep domain understanding
  • Long-term accountability
  • Careful trade-offs
  • Awareness of failure modes
  • Conservative change management
  • Institutional memory

AI can assist here — but it cannot replace the judgment required to build systems that must not fail.

This is why AI has not replaced senior engineers.

It has instead made the distinction between disposable and durable code more important than ever.

Businesses Built on Disposable Code

One of the most interesting side effects of AI is how it enables businesses to exist almost entirely on disposable software.

Examples include:

  • Micro-SaaS products
  • One-feature tools
  • Niche automation services
  • Short-lived integrations
  • Campaign-based or event-based software

These businesses succeed by optimizing for:

  • Speed
  • Learning
  • Adaptability
  • Market fit

Not durability.

Trying to apply durable-code discipline here often slows things down unnecessarily.

The Dangerous Middle Ground

The most dangerous software lives in the middle.

Code that:

  • Was generated quickly
  • Shipped as disposable
  • Accidentally became critical
  • Was never redesigned for durability

AI has made this category much larger.

The moment disposable code becomes business-critical, a conscious transition must happen.

Someone must decide:

“This now needs to survive.”

That decision requires engineers — not generators.

Durable Code Requires a Different Engineering Culture

Durable systems cannot be built with disposable-code habits.

They require:

  • Strong fundamentals
  • System-level thinking
  • Respect for stability
  • Conservative change
  • Deep observability
  • Testing that reflects real failure modes

They value:

  • Boring solutions
  • Proven patterns
  • Incremental improvements
  • Reliability over novelty

And above all, they require great engineering teams.

Why Great Engineers Matter More in an AI World

As tools improve, the bottleneck moves.

The hardest part is no longer writing code.

It is:

  • Knowing what should exist
  • Knowing what must not break
  • Knowing what can safely change
  • Knowing when speed is acceptable — and when it is not

Durable code is about trust.

Trust that:

  • This system will work tomorrow
  • This change will not cascade into failure
  • This decision will not harm the business years from now

That trust is built by people, not prompts.

Choosing the Right Kind of Code

Before writing code, ask:

  • Is this expected to live for years?
  • Will failure be costly?
  • Will many depend on it?
  • Will change be slow and careful?

If yes — you are writing durable code.
Treat it accordingly.

If not — write disposable code fast, learn, and move on.

Both are valid.
Both are necessary.

Confusing them is where problems begin.

Final Thought

AI has not blurred the line between disposable and durable code.

It has made the line sharper than ever.

Disposable code is cheaper, faster, and more abundant.
Durable code is rarer — and more valuable.

Disposable code helps us explore the future.
Durable code keeps the world running.

And the best engineers always know which one they are building.