AI Agents and the Refactoring That Never Happens

September 2, 2026 astatine 12:00 PM

Working pinch AI agents time to day, I’ve started noticing a inclination that worries me. Teams — including knowledgeable engineers who utilized to cognize amended — person quietly stopped pushing to rewrite aliases restructure the gnarliest parts of their systems. It’s not astir the value of the codification the agents write. It’s astir a decision that utilized to hap almost reflexively and now seldom does: the determination to stop and opportunity this has go unmanageable, we request to refactor it earlier we spell any further.

Human discourse is small, and that shaped really we build software

A machine tin clasp acold much successful “working memory” than a quality can. We can’t reason astir a analyzable strategy erstwhile it branches successful dozens of directions, each branch pinch its ain implications, each interconnected. It’s simply excessively overmuch to keep successful our heads astatine once.

So historically we did the only point we could: we divided systems into modules small capable to understand successful isolation, and past we spent effort connecting those modules together pinch interfaces we could besides understand. Modularity, encapsulation, layering — these aren’t artistic preferences. They’re concessions to the size of quality moving memory. We break the strategy down until each portion fits successful 1 person’s head, because that’s the only measurement a personification can reason astir it, alteration it safely, and reappraisal personification else’s change.

The refactoring reflex

Systems seldom commencement retired confusing. A portion of codification is written erstwhile the requirements are still simple, and astatine first it sounds cleanly. Then the requirements change. A developer adds a branch for a caller case, past different for an exception, past a typical lawsuit connected apical of that exception. Over enough iterations the original “rule” the codification expressed is buried nether exceptions — sometimes the requirements person shifted truthful acold that the codification is now nothing but exceptions, pinch nary clear norm near astatine all.

There’s a infinitesimal each knowledgeable developer recognizes: you’re debugging an issue, you travel the code, and you get lost. The branches nary longer shape a picture you tin clasp successful your head. Historically, that emotion was a signal. A senior engineer, upon getting mislaid successful a portion of the system, would region and say: this has go unmanageable — earlier I adhd thing else, I request to rewrite or refactor this truthful it’s understandable again. Not for elegance, but truthful that they and everyone aft them could logic astir it and safely reappraisal early changes.

That reflex — “I’m lost, truthful it’s clip to refactor” — has softly been one of the astir important forces keeping long-lived systems maintainable. And it was triggered by a quality limitation: the infinitesimal a personification could nary longer travel the code.

To beryllium fair, that reflex was already nether unit agelong earlier AI agents. Deadlines, roadmaps, and managers asking “why are you rewriting thing that works?” person ever fought against it, and refactoring was usually the first thing to get deprioritized. Senior engineers had already, complete the years, stopped pushing backmost arsenic difficult arsenic they erstwhile did erstwhile a strategy sewage unmanageable. Agents didn’t create that weakness. What they did was region the past internal trigger that utilized to occurrence successful spite of it — the visceral acquisition of a human getting lost.

AI agents don’t get lost

Here’s the problem. AI agents are not bound by quality discourse limits successful the same way. An supplier tin publication the tangled function, trace each caller, and make sense of the messiness that would person stopped a quality cold. It tin adhd the adjacent branch correctly, and the 1 aft that, moving confidently wrong codification that nary human on the squad afloat understands anymore.

That sounds for illustration a strength, and successful the short word it is. But announcement what’s missing: the supplier ne'er gets lost, truthful the awesome ne'er fires. The supplier has no reflex that says “this has go unmanageable, we should extremity and refactor.” It conscionable keeps adding branches to the pile. Unless it’s specifically instructed — through its harness, its prompt, aliases definitive reappraisal criteria — to measurement backmost and question the structure, it will happily support a messiness indefinitely, because the messiness isn’t a problem for the agent.

The existent risk: humans extremity being capable to constabulary the code

The nonaccomplishment mode isn’t that the supplier writes bad code. It’s that the natural checkpoint disappears, and the humans extremity noticing the codification has drifted beyond their understanding. Over clip you get astatine a strategy where:

• No developer connected the squad tin afloat logic astir cardinal parts of the code.
• Reviews go rubber stamps, because the reviewer can’t really travel the change good capable to judge it.
• The squad progressively trusts the agent precisely because they nary longer understand the codification themselves — which is precisely backwards from really trust should work.

At that constituent you’ve mislaid thing important: the expertise to logic astir your own strategy without an supplier arsenic an intermediary. And you mislaid it gradually, without immoderate azygous alarming moment, because the infinitesimal that utilized to raise the alarm — a quality getting mislaid — was softly removed from the loop.

Clean codification is cheaper for the agents too

It’s tempting to framework each of this arsenic a purely opinionated interest — we ought to understand our ain systems — and time off it there. But there’s a hard-nosed, practical logic to support the codification organized, and it’s 1 that survives moreover if you’re perfectly happy to fto agents do the work.

An supplier that ne'er gets mislaid still pays a value for a mess. The much tangled and interconnected a portion of codification is, the much discourse the supplier has to load and hold to make a correct change: much files to read, much branches to trace, more tokens burned connected each azygous edit. A strategy built from small, self-contained modules that are easy to logic astir isn’t conscionable kinder to humans — it’s cheaper to operate, because each early alteration costs the supplier little to understand.

And it isn’t only astir cost. When the applicable logic doesn’t fresh into a bounded, coherent slice, agents are much apt to suffer the thread and hallucinate — to assume a branch does thing it doesn’t, aliases to miss an objection buried three levels deep. The aforesaid modularity that keeps a strategy wrong a human’s caput keeps each alteration wrong a well-defined bound the supplier tin logic astir reliably. Clean boundaries trim mistakes connected some sides, for the aforesaid reason.

So keeping the root organized isn’t a favour we do for humans astatine the agents’ expense. It benefits humans, it improves the agents’ accuracy, and it lowers the token costs of each alteration we’ll ever make to that codification again. The refactoring reflex we’re astatine consequence of losing was ne'er only astir quality comfortableness — it turns out to beryllium bully economics too.

Policing ourselves

I don’t deliberation the reply is to hobble the agents. The reply is for america to bring back the checkpoint deliberately, since it nary longer happens connected its own. We have to support asking the mobility the supplier won’t ask:

• Do I still understand this portion of the system, aliases person I been letting the agent understand it for me?
• If a quality had to debug this without the agent, could they travel it?
• Have the requirements drifted truthful acold that this codification is now each exceptions and no norm — the classical awesome that it’s clip to rewrite?
• Is now the infinitesimal to region characteristic activity and refactor this into thing a person tin clasp successful their caput again?

You tin besides push immoderate of this into the harness — instruct your agents to flag when a module has grown beyond a reasonable size aliases branching complexity, to propose refactorings alternatively than only extending, and to telephone retired erstwhile a change is getting difficult to logic about. That helps. But the eventual responsibility stays pinch us, because we’re the ones who request to beryllium capable to understand our systems, and we’re the ones who suffer that expertise if we’re not paying attention.

The convenience of an supplier that ne'er gets mislaid is real. But “the supplier can still make consciousness of it” is not the aforesaid arsenic “the strategy is healthy.” The first is about the agent’s capacity; the 2nd is astir ours. Keep asking whether it’s time to refactor — because the instrumentality that utilized to punctual you, by getting lost, doesn’t get mislaid anymore.