Never write an article about good system design.

In all seriousness, this is an extraordinary subtle and complex area, and there are few rules.

For example, "if you need data from multiple tables, JOIN them instead of making separate queries and stitching them together in-memory" may be useful in certain circumstances. For highly scalable consumer systems, the rule of "avoid joins as much as possible" can work a lot better.

There is also no mention of how important it is to understand the business - usage patterns, the customers, the data, the scale of data, the scale of usage, security, uptime and reliability requirements, reporting requirements, etc.

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graphviz 5 days ago | parent [-]

And by "system" we mainly meant "transactional website."

	▲	whodidntante 5 days ago \| parent [-]
		And this is the point. You need to narrow the scope to make something like this useful. Writing a paper on "Good transportation design" is kind of meaningless. Do you mean cars, trucks, boats, planes, spacecraft, scooters, fighters, tanks ? Do you mean roadways that can accommodate some subset ? If you mean "transactional websites", and assuming you mean something like product catalogs and being able to purchase, that narrows it down quite a lot. Or does it ? For the majority of use cases, Craigs list, ebay, Amazon are the best fit. Next in number of use cases are Wix/Square/etc where you design your UI. Then comes all in one systems with UI/ORM based on Python/Ruby/etc where you need to design your own DB schema and UI, but the "design" is already done for you. The next step is custom designed systems like the one the article talks about, where complete off the shelf is not suitable And then there are the highly scalable systems The article is perfectly fine if we are discussing custom designed but not necessarily the highest in scalability.