Back to Growth Notes

AI coding tools were supposed to make developers sharper. Instead, they are making most teams careless. Four AI coding mistakes that quietly destroy software quality.

AI was supposed to make developers sharper. Instead, it is making most of them sloppier. The same teams that adopted Claude Code, Copilot and a dozen AI coding tools last year are now shipping more bugs per release than they did before. The features they ship are bigger, faster to write, and less understood by the person who merged them.

So what happened? The technology works. The people using it changed how they show up. AI coding mistakes are quietly becoming the biggest threat to software quality in 2026, because when AI does the thinking for you, you stop thinking.

The promise versus the reality

Two years ago, the pitch was simple. AI would handle the boilerplate, draft the tests, summarise the diff, and free developers to spend more time on the hard problems. Productivity would go up. And the math seemed right: if a developer spent 40 percent of their time on repetitive code, and AI took most of that away, output should climb.

Output did climb. Quality did not follow it. A language model returns an answer that is correct in form, which is not the same as correct in substance, and the gap between those two only shows up once the code is running against real data, not while it looks plausible in the editor.

Four AI coding mistakes that quietly destroy quality

1. Trusting output because it compiles

Code that runs is not code that is correct. A function can pass every syntax check, satisfy the type system and still do the wrong thing on the one input that matters. Teams that stop reading generated code because “it works” are grading on the wrong criterion, and the failure only shows up in production, weeks later, far from the commit that caused it.

2. Skipping the test because the AI already checked it

A model can write a test. It cannot decide, on its own, whether that test actually exercises the failure mode that matters, or whether it was written to pass rather than to catch anything. A test that can never fail proves nothing, and a team that treats an AI-written test suite as verification, without checking whether the tests are strict enough to fail, has verification in name only.

3. Letting review muscle atrophy

Reading code critically is a skill, and like any skill it degrades without practice. A developer who stops writing the tricky parts by hand also stops noticing when generated code takes a shortcut that will not scale, because the part of the brain that used to catch it has not been exercised in months. The team gets faster and, quietly, worse at the one thing that used to catch expensive mistakes before they shipped.

4. Letting the model own architecture decisions

An agent asked to add a feature will add it in the most locally sensible way, not the way that fits the system three features from now. Nobody decided the database should get a fourth ad hoc table, or that this service should call that one directly instead of through the interface everything else uses. It accumulated, one plausible-looking change at a time, because nobody was assigned to own the shape of the system as a whole.

AI reflects the discipline of the person using it, and the wrong discipline gets amplified, not corrected.

What sharper actually looks like

The fix is not writing less code by hand and reviewing it less. It is the opposite discipline, applied consistently. Tests that can actually fail, not tests written to pass. Mutation checks on every repair, so a fix that does not change behaviour under a broken input gets caught before it ships. Independent adversarial review rounds alongside the team’s own tests, so the agent that built something is not the only judge of whether it is right. Verification on the running system, not on a green build, because a build can be green and still be wrong about the one case that matters to a real customer.

Done properly, one developer works at the pace of three without the quality of zero. Done carelessly, the same setup produces speed first and unmaintainable software second, and the bill for that arrives later, in a system nobody fully understands anymore.

The ODB Way

At ODB Growth, AI agents do implementation, analysis and review, inside a process built to catch exactly the four mistakes above. Architecture decisions, quality criteria and final accountability stay with the person who scoped the work, not with the model that wrote the diff.

That is not a slogan. It is the daily discipline behind every engagement: verify before you trust, measure before you ship, and never let speed replace judgement about what the software is actually supposed to do.

Onno de Bel

Onno de Bel

AI Engineer & Architect | ODB Growth

Ready to build something
that moves a number?

Let's find out where AI actually pays in your process, and build it.

Plan a Growth Call