Perfectly possible IME, it just requires more time. Even if you understand all the (important) parts of your code and validate it, Ai still helps with productivity a lot. It's just not as fast as blindly vibe coding - not at first at least. Agents on their own without checks, and superficial prompts without understanding, result in agents either introducing bugs, or if you have an appropriate test harness, painfully slow, in my experience. It requires skill to use an agent effectively.