The blog post this is written about can be found here.

This blog post by a software engineer working at Facebook outlines several anti-patterns, including examples, why they’re bad, how to avoid them, and why it’s difficult to avoid them. I chose it to read because of the obvious connection to the course material, my continuing desire to avoid bad practices, and the fascinating connections the blogger makes to the cognitive biases that explain why we fall into these traps.

Some of the anti-patterns are time-wasters, like bikeshedding and analysis paralysis. Bikeshedding is described as the tendency to spend a disproportionate amount of time debating unimportant details. The blogger suggests flipping a coin or voting when you notice this problem arising. You can resolve to revisit the decision at a time when it’s more relevant, as long as you get the decision over with quickly and move onto more important ones.

Analysis paralysis is analyzing so much that it impedes progress. The blogger suggests that this anti-pattern crops up due to information bias and validity bias. Information bias is defined as the belief that you can make better decisions the more information you have, regardless of whether the information is relevant to the decision. Validity bias is overestimating how accurately you can predict an outcome based on a set of information, even if that information is unreliable or outdated. These can lead us to the belief that more analysis will be useful, even when it won’t. His solution to this anti-pattern is more iterations of code. If you go ahead and try something, you can see actual outcomes and modify your code accordingly, instead of endlessly speculating about outcomes.

I also took note of several class-related anti-patterns. These include the god class, a class that knows about and/or controls too many classes; fear of adding classes, the avoidance of adding classes due to a misconception that they will make designs more complicated; and the poltergeist class, a useless class that ought to be eliminated. The solutions for the first two seem to contradict the solution to the last one, but taking all three into account leads to a clear picture of how to properly use classes.

For the fear of adding classes, the blogger gives a useful example of a tangled ball of yarn to represent too few classes. Adding classes can instinctively feel like adding complexity, but simplifying your design with additional classes is akin to separating the yarn into individual strands. Similarly, the god class can be broken up according to the single-responsibility principle, giving classes only one clearly-defined responsibility. Poltergeist classes lack a clear responsibility; they often only call other classes or add a layer of abstraction that isn’t actually necessary. When you create a new class, you should make sure it actually has a valuable role and simplifies the design.

Hopefully, having read this, I will be able to recognize these anti-patterns in the future and apply their relevant solutions.


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