What Happens When AI Writes Code No One Understands?

Peter Langewis ·
Senior developer studying unfamiliar code on a glowing monitor in a dim Amsterdam office, expression tense, screen light reflecting in glasses.

When AI writes code no one understands, the result is working software that becomes a liability the moment something goes wrong. The code runs, but no developer on the team can confidently explain what it does, why it makes certain decisions, or how to fix it when it breaks. This creates a fragile codebase that erodes team confidence, slows delivery, and introduces serious operational risk. The questions below unpack exactly why this happens and what engineering teams can do about it, especially as AI-assisted coding becomes a standard part of the development workflow in 2026.

Can developers actually maintain code they didn’t write?

Yes, developers can maintain code they didn’t write, but only when that code follows clear conventions, includes meaningful documentation, and reflects patterns the team recognizes. The real challenge with AI-generated code is not authorship but legibility. When AI produces code that lacks context, explanation, or consistent structure, maintenance becomes guesswork rather than engineering.

Traditionally, developers inherit code from colleagues and learn to navigate it through comments, commit histories, and team knowledge. AI-generated code often strips away that human context. There are no design decisions explained in a pull request, no colleague to ask why a particular approach was chosen, and no shared memory of what problem the code was actually solving. Maintenance then depends entirely on how readable and well-structured the AI output is, which varies significantly depending on the tool, the prompt, and the level of human review applied before the code was merged.

What makes AI-generated code hard to understand?

AI-generated code is hard to understand primarily because it optimizes for correctness rather than clarity. Large language models produce code that passes tests and satisfies requirements, but they do not naturally explain their reasoning, follow team-specific conventions, or account for the broader architectural context of a codebase. The result is technically functional code that lacks the narrative a human developer would leave behind.

Several specific factors compound this problem:

  • Lack of intent documentation: AI rarely explains why a solution was chosen over alternatives, which is often the most valuable information for future maintainers.
  • Inconsistent style: AI tools generate code based on patterns across vast training data, which can produce stylistic inconsistencies that clash with existing team conventions.
  • Over-engineering or under-engineering: Depending on the prompt, AI may produce unnecessarily complex abstractions or oversimplified implementations that don’t scale.
  • Opaque logic in edge cases: AI handles edge cases in ways that may not be obvious, and without comments or tests that explain the expected behavior, these become invisible traps.
  • Context blindness: AI tools generate code based on the immediate prompt, not the full history and architecture of the system it is being integrated into.

What are the real risks of deploying code no one understands?

Deploying code no one fully understands introduces risks across security, reliability, and compliance. When a bug surfaces in production and no developer can trace the logic quickly, incident response slows dramatically. When a security vulnerability is discovered, the team may not know how far it extends through the codebase. And when regulatory audits require explainability, opaque AI-generated logic creates a direct compliance problem.

Beyond immediate incidents, the long-term risk is architectural drift. Each piece of unreviewed AI-generated code that enters the codebase adds to a growing layer of logic that the team treats as a black box. Over time, teams stop modifying certain modules because they are afraid of breaking something they do not understand. This is sometimes called “fear-driven development,” and it significantly reduces a team’s ability to iterate and innovate. In regulated industries such as financial services or logistics, where auditability is a legal requirement, this risk is especially acute.

How does unreadable code affect software development teams?

Unreadable code directly degrades team productivity, morale, and knowledge transfer. When developers cannot understand the code they are working with, onboarding new team members takes longer, debugging sessions stretch from hours to days, and the team’s collective confidence in the system declines. Over time, this creates a culture where developers avoid touching certain parts of the codebase, which concentrates risk and reduces agility.

There is also a skill development concern. Junior developers who work primarily with AI-generated code they do not understand miss the learning opportunities that come from reading and reasoning through well-crafted code. Senior developers who rely too heavily on AI output without reviewing it critically may find their own architectural judgment weakening over time. A team’s long-term technical capability depends on its members actively understanding the systems they build, not just shipping code that works today.

What’s the difference between AI-assisted and AI-autonomous code generation?

The key distinction is the degree of human involvement in the output. AI-assisted coding keeps a developer in the loop at every step: the AI suggests, the developer reviews, understands, and decides. AI-autonomous code generation removes that review step, allowing the AI to produce and sometimes deploy code with minimal human oversight. The first model preserves comprehension; the second trades it for speed.

AI-assisted coding

In an AI-assisted model, tools like code completion, inline suggestions, and AI-powered review act as accelerators for human developers. The developer still makes architectural decisions, reads the generated output critically, and takes ownership of what gets committed. This approach improves productivity without sacrificing understanding, because the human remains the decision-maker throughout the process.

AI-autonomous code generation

In an autonomous model, AI agents write entire features, services, or modules based on high-level instructions, sometimes with automated testing as the only gate before deployment. While this can dramatically increase output volume, it creates exactly the comprehension gap described throughout this article. The code ships, but the team’s understanding of it is shallow, and the risks outlined above begin to accumulate immediately.

How can engineering teams keep AI-generated code under control?

Engineering teams can keep AI-generated code under control by establishing clear review standards, documentation requirements, and architectural guardrails that apply to all code regardless of its origin. Treating AI-generated code as a first draft that requires the same scrutiny as any human-written code is the most effective starting point.

Practical steps that make a measurable difference include:

  • Mandatory human review: No AI-generated code should be merged without a developer who can explain what it does and why it belongs in the codebase.
  • Documentation as a requirement: Teams should require that AI-generated code be documented to the same standard as manually written code, including inline comments that explain non-obvious decisions.
  • Test coverage as a proxy for understanding: Writing tests for AI-generated code forces developers to reason through its behavior, which surfaces misunderstandings before they reach production.
  • Architectural boundaries: Defining clear boundaries for where AI-generated code is acceptable limits the blast radius of any comprehension gaps.
  • Regular code walkthroughs: Team sessions where AI-generated code is reviewed collectively build shared understanding and catch issues that individual review misses.
  • Incremental adoption: Introducing AI tools gradually, starting with lower-risk areas, gives teams time to develop the habits and standards needed to use them responsibly.

How Bloom Group helps teams use AI-assisted coding responsibly

We understand that AI-assisted coding is not a shortcut to skip engineering judgment. It is a capability multiplier that only works when the team using it has the technical depth to evaluate, guide, and own what the AI produces. At Bloom Group, we bring exactly that depth to every engagement.

Our team consists of developers with academic backgrounds in Computer Science, AI, Mathematics, and related disciplines, which means we do not just use AI tools, we understand how they work and where they fall short. When we support organizations in integrating AI into their development workflows, we focus on:

  • Establishing review and documentation standards that keep AI-generated code legible and maintainable
  • Designing architectural guardrails that prevent AI autonomy from outpacing team comprehension
  • Embedding the right mix of AI-assisted and human-led development for your specific risk profile and industry requirements
  • Supporting teams across financial services, logistics, manufacturing, and other regulated sectors where code explainability is not optional
  • Offering Team as a Service (TaaS) models that bring experienced engineers into your workflow without the overhead of building from scratch

If your organization is navigating the balance between AI productivity and code quality, we are ready to help you build a development practice that delivers both. Get in touch with us to start the conversation.

Frequently Asked Questions

How do I know if my team's AI-generated code has already become a liability?

Key warning signs include developers hesitating or refusing to modify certain modules, recurring bugs in areas where AI was heavily used, onboarding taking significantly longer than expected, and an inability to explain code behavior during incident postmortems. If your team regularly describes parts of the codebase as u0022black boxesu0022 or relies on the code u0022just working,u0022 that is a strong signal that comprehension debt has already accumulated. A structured code audit focused on documentation coverage, test quality, and architectural consistency can help you quantify the problem before it escalates.

What should a mandatory code review checklist for AI-generated code include?

At minimum, a review checklist for AI-generated code should verify that the reviewer can independently explain the logic without referencing the AI tool that produced it, that inline comments address non-obvious decisions, that edge cases are covered by tests with clear intent, and that the code aligns with existing architectural patterns. Adding a specific prompt-documentation requirement — where the developer records what instruction was given to the AI — can also help future maintainers understand the original intent. Think of it as the equivalent of a commit message, but for the AI interaction itself.

Can AI tools be configured or prompted to produce more readable, maintainable code?

Yes, prompt engineering has a significant impact on the quality and legibility of AI-generated output. Explicitly instructing the AI to follow your team’s style guide, explain its reasoning in comments, flag edge cases, and prefer simplicity over cleverness will consistently produce better results than open-ended prompts. Some teams embed these instructions into shared prompt templates or system-level configurations within their AI tools so that quality standards are applied consistently across the team rather than depending on individual developer habits.

How do we handle AI-generated code that is already in production and poorly documented?

The most practical approach is incremental remediation rather than a full rewrite. Start by identifying the highest-risk modules — those that are frequently modified, involved in security-sensitive operations, or lack any test coverage — and prioritize those for documentation and test backfill. Pair senior developers with the affected code during the next natural change cycle so that understanding is rebuilt through active engagement rather than passive reading. Avoid the temptation to replace poorly understood code with more AI-generated code without the review standards now in place to prevent the same problem from recurring.

What is the right balance between AI-generated and human-written code on a professional engineering team?

There is no universal ratio, but the right balance is determined by your team’s review capacity, the risk profile of the system, and the regulatory requirements of your industry. A useful guiding principle is that AI should never generate more code than your team can meaningfully review and own in the same sprint. In regulated sectors such as financial services or logistics, where auditability is a legal requirement, human oversight of AI output is not optional regardless of the efficiency gains on offer. Starting with AI assistance in lower-risk areas and expanding based on demonstrated review maturity is a responsible adoption path.

How does AI-generated code affect junior developers on the team, and what can we do about it?

Junior developers who consume AI-generated code without critically analyzing it miss the foundational learning that comes from reading, reasoning through, and debugging well-crafted code. Over time, this can create engineers who are proficient at prompting but weak in core problem-solving and architectural thinking. Teams can counter this by pairing juniors with senior reviewers specifically during AI code review sessions, assigning them ownership of understanding and documenting AI-generated modules, and ensuring they still write meaningful portions of code independently to develop and maintain core engineering judgment.

Is there a point at which a team should avoid using AI code generation altogether?

AI code generation should be avoided or heavily restricted in areas where explainability is non-negotiable and review capacity is insufficient to match output volume. Specific scenarios include security-critical authentication and authorization logic, compliance-sensitive data processing pipelines, and any module where the team cannot allocate a qualified reviewer who genuinely understands the domain. The decision is not about the AI tool itself but about whether your team has the bandwidth and expertise to responsibly own what it produces — if the answer is no, slowing down is the higher-quality choice.

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