I’ve seen this play out a couple time. I agree about a lot of what you said and this is indeed true that you can have very senior and very knowledgeable devs basically “hack” or “bulldoze” their way into a backlog, I would personally argue that this is not a decent or desirable behavior.

There is no such thing as “small finition”. Making sure that a change or a feature works all the way through is not finition, it is core to the task, and you can’t expect someone else to digest and do the latter half of the work without being in your head.

I guess I am too lazy to type out all the examples with the downfall, but basically if you allow this, you will be shielding a senior from his own butched work, and lets be honest, most people who do this skip the “boring” work for their own selfish reasons. If they want to split the task and have you fix the tests, have them spell it out and justify it.

Management might not understand what is going on, all they might see is a superstar flying through the backlog, while everyone else struggle because they’re constantly fixing this guy’s shit. This rarely lead to good engineering, or team dynamic, or team management, and of course you end up with this one guy claiming credit for so much shit, while other team members stagnate. Unfortunately appearance is a thing in dev work, as much as I wish it wasn’t.

What you seem to be describing is one big module with lots of responsabilities, and not circular dependency. Personally, I don’t think it is ideal, and I don’t know about your specific case so I could be wrong, but I have never seen a legit case for bloated classes. That being said, making a big module is still much better than splitting it into inter-dependant modules. Modules that know each other are so cohesive that they might as well be the same module anyway.

To add onto the circular dependency problem, it is not just about readability and cognitive load (though there is some of that), but cyclic dependencies actively break things, and make it much harder to manage the lifecycle of a program. No dependency injection, poor memory management, long compile times. It is a huge hack, and I understand that you think it can be the proper solution sometime, but it is really just a bad thing to do, and it will bite you some day.

It does not get more complicated to split your example. What gets more complicated is giving all sort of unrelated responsabilities to a single class, simply because it is the path of least resistance.

In your example, all you need is an extra module listening for configuration changes and reacting to it. This way you leave your context-specific logic out of your data model, no need for cyclic dependency. There are so many downsides to cyclic dependency, to justify it because splitting your logic is “too complicated” really isn’t a strong argument.