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460 points pieterr | 1 comments | | HN request time: 1.011s | source
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__turbobrew__ ◴[] No.42159121[source]
It’s interesting, SICP and other many other “classic” texts talk about designing programs, but these days I think the much more important skill is designing systems.

I don’t know if distributed systems is consider part of “Computer Science” but it is a much more common problem that I see needs to be solved.

I try to write systems in the simplest way possible and then use observability tools to figure out where the design is deficient and then maybe I will pull out a data structure or some other “computer sciency” thing to solve that problem. It turns out that big O notation and runtime complexity doesn’t matter the majority of the time and you can solve most problems with arrays and fast CPUs. And even when you have runtime problems you should profile the program to find the hot spots.

What computer science doesn’t teach you is how memory caching works in CPUs. Your fancy graph algorithm may have good runtime complexity but it completely hoses the CPU cache and you may have been able to go faster with an array with good cache usage.

The much more common problems I have is how to deal with fault tolerance, correctness in distributed locks and queues, and system scalability.

Maybe I am just biased because I have a computer/electrical engineering background.

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soegaard ◴[] No.42159469[source]
Have you seen

"Software Design for Flexibility: How to Avoid Programming Yourself into a Corner" by Chris Hanson and Gerald Jay Sussman

It's from 2021.

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pipes ◴[] No.42159520[source]
I hadn't, that looks excellent.
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ralphc ◴[] No.42160904[source]
IMO it's not excellent. It's not like SICP, it's obtuse for no reason, I find it a hard slog. Flexibility is good but it seems to try to make every bit of your program flexibile and pluggable and you just need to do something eventually.

My opinion, I'd welcome others on the book; there was a small splash when it came out but not much discussion since.

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gregmac ◴[] No.42161097[source]
I haven't read the book, but my experience is that the way to make things flexible is to make them simple as possible.

When I've used (or built) something that was built in the style like you're talking about, it's almost always wrong, and the extra complexity and stuff now makes it harder to do right. It's not surprising: unknown future requirements are unknown. Over building is trying to predict the future.

It's like someone building a shed and pouring a foundation that can work for a skyscraper. Except it turns out what we needed was a house that has a different footprint. Or maybe the skyscraper is twice the height and has a stop for the newly-built underneath. Now we have to break apart the foundation before we can even begin work on new stuff; it would have been less work if the original just used a foundation for a shed.

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1. zelphirkalt ◴[] No.42168434[source]
I think that is what the book does. Step by step introducing new requirements, by telling you about a situation, where the previous code would not be flexible enough. I am sure it doesn't state, that one should apply all of its ideas all the time, regardless of the project at hand.