Comment by maxwellg | Hacker News Reader

Comment by maxwellg | Hacker News Reader

I never really understood putting consistency on a pedestal. It's certainly nice when everything operates exactly the same way - but consistency for consistency's sake is awful to work in too. If a team realizes that logging library B is better than library A, and but NEVER switches from A to B because of consistency concerns, then in two years they'll still all be using inferior tools and writing worse code. Similarly, if a team DOES decide to switch from A to B, they probably shouldn't spend months rewriting all previous code to use the new tool. It's ok for multiple established patterns to live in the same codebase, so long as everyone has an understanding of what the "correct" pattern should be for all new code.

The consistency that they're referring to specifically is to do with consistency in the way that certain features or functionality is implemented.

To make your example match, it would be more so that there are two teams A and B, Team A already created a framework and integration for logging across the entire application. Team B comes along and doesn't realize that this framework exists, and also invents their own framework and integration for logging.

This is the type of consistency that the author points to, because Team B could have looked at other code already referencing and depending on the logging framework from Team A and they would have avoided the need to create their own.

It's about minimizing cognitive load.

"Consistency for consistency's sake" is usually a misinterpretation of "Consistency because there are reasons for the way things are already done and you don't understand those reasons well enough to diverge". If you understand the current system completely, then you can understand when to diverge from the system (though this is usually better expressed as "when to improve the system" rather than doing something completely new). If you don't understand the current system, then you can't possibly ensure that you haven't missed something in your shiny new way of doing things.

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