You not only stumble upon a weird bug in your hacky solution that takes engineering weeks to debug, but your interfaces are fragile so feature velocity drops (bugs reproduce and unless you address reproduction rate you end up fixing bugs only) and things are so tightly coupled that every two line change is now multi-week rewrite.

Look at e.g. facebook. That site has not shipped a feature in years and every time they ship something it takes years to make it stable again. A year or so ago facebook recognized that decades of fighting abuse led them nowhere and instead of fixing the technical side they just modified policies to openly allow fake accounts :D Facebook is 99% moltbook bot-to-bot trafic at this point and they cannot do anything about it. Ironically, this is a good argument against code quality: if you manage to become large enough to become a monopoly, you can afford to fix tech debt later. In reality, there is one unicorn for every ten thousand of startups that crumbled under their own technical debt.

> You not only stumble upon a weird bug in your hacky solution that takes engineering weeks to debug, but your interfaces are fragile so feature velocity drops (bugs reproduce and unless you address reproduction rate you end up fixing bugs only) and things are so tightly coupled that every two line change is now multi-week rewrite.

I don't think you fully grasp the issue you're discussing. Things don't happen in a vacuum, and your hypothetical "fragile interfaces" that you frame as being a problem are more often than not a lauded solution to quickly deliver a major feature.

The calling card of junior developers is looking at a project and complaining it's shit. Competent engineers understand tradeoffs and the importance of creating and managing technical debt.