Ran Aider for a week on a medium-sized internal tool project. Primary goal: speed up boilerplate and CRUD logic.
Net result: I wrote about 40% fewer lines of code myself. But the bug rate in the new code is roughly 20% higher than my baseline. The trade-off is real.
Most errors were subtle logic misreads—Aider would implement a filter slightly wrong, or misplace a conditional. It saved time on structure, but debugging its "help" ate into that savings. It's not a net positive yet for production work where correctness is critical. For prototyping or generating repetitive scaffolding, it has legs. For business logic, it's a risky time-saver.
Your experience matches what I've seen when integrating these tools into client workflows. The 40% reduction in manual code writing is compelling for project scoping, but that 20% bug increase is the hidden tax.
The subtle logic errors, like filter misplacement, are particularly dangerous because they pass a superficial review. I've started treating AI-generated business logic as a first draft that requires a specific verification step. I'll have it write the function, then immediately write the unit test for that function myself. The test often catches the semantic gap the AI created.
For pure API scaffolding or webhook stubs, the risk/reward is much better. It's the conditional logic, especially around edge cases, where it still struggles with intent.
- Mike
That 20% bug increase is the killer. It's not just a "hidden tax", it's a direct injection of security debt and audit risk.
You're introducing subtle logic flaws that automated SAST tools won't catch because the code looks syntactically correct. A misplaced filter or conditional could easily become an authorization bypass or data leak in a CRUD context. The time you spend debugging is now, the time you spend responding to an incident because of it is later.
If correctness is critical, and you know it is, then it's not a trade-off. It's a net negative. You've outsourced part of your core thinking to a system that gets the semantics wrong. That's not a tool for production, it's a liability.
— geo
You've hit on the survivorship bias in all those glowing testimonials. People celebrate the 40% fewer lines written because it's easy to measure. They don't track the downstream hours lost chasing those subtle logic misreads.
The risk is you start to treat its output as a finished product, not a first draft with a 20% chance of being semantically wrong. That's when the time savings evaporate completely. For boilerplate, fine. But letting it handle a filter or conditional is basically introducing a junior dev who is confidently wrong and can't explain their reasoning.
Your mileage will vary