To correctly vibe code something useful, I find that I need to religiously give faith to the tool and forget all about SWE principles and best practices and instead treat it like a child who makes mistakes and corrections while the adult must not intervene or admonish too much but rather nudge it to right direction.

Also vibe code has a parallel feature, while the code is generating, you are also doing live review and correcting it towards right direction, so depending on your experience, the end product can be a bad mess or wonderful piece of creation and maintenance dream.

The issue with seasoned SWE is that, the moment a mistake(or bad pattern) is made, the baby is thrown with bath water.

For a tiered app like the one presented, 35k LOC is not really that impressive if you think about it. A generic react based front end will easily need a large number of LOC due to modular principle of components, various amounts of hooks and tests(nearly makes us 25-40% of LOC). A business layer will also have many layers of abstractions and numerous impl. to move data between layers.

The vibe code shines, when you let it build one block at a time, limit the scope well and focus. Also, 2-3 weeks is a lot of time to write 35k LOC. at start of any new project, LOC generation rate is very high. But in maintenance phase it significantly falls as smaller changes are more common.