It depends on how it’s built. Anyone vibecoding without a plan will run into this very quickly. However, if a project is planned out in advance, broken down into multiple milestones, with measurable goals and thorough testing at each milestone before moving forward, the LLM can create surprisingly well-structured and solid code which fits the overall structure.

Basically, the more thought, planning, and structure is worked out before anybody runs even a single prompt, the better your results will be. And continual testing with the goal of finding every single weak point will give even better results. But planning it out ahead of time and doing all that testing takes a lot of time and human effort, and nobody vibecoding slop apps is doing that.