> They made him do it again and he passed.

I would hire the "just use postgres" dude in a heartbeat without re-testing, if the numbers made sense, and perhaps give a stern talking-to to the interviewers. But then again I'm not a unicorn founder, so what do I know.

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lucianbr an hour ago | parent | next [-]

My read of the story is that the decision to hire was already made, the interviewer goofed but was then set on the right track by his boss.

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PKop 2 hours ago | parent | prev [-]

Eh, it's a good answer and shows good instincts, but they still want to know how he would design a system if one was necessary. There's no need to be ridiculous about any of this from either perspective, which is why it should never have been a "fail" without the original interviewer simply saying "That's a solid answer now tell me what you would do if you had to build something new". I mean look how much time he wasted for everyone including his own CEO by being stubborn about it.

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MrBuddyCasino 2 hours ago | parent [-]

If the numbers can be satisfied by a Postgres then thats the correct answer. The interviewers fucked up, because they sized the problem wrongly.

This is the same issue that was prevalent when the industry switched from HDD to SSD: some system design questions suddenly became trivial, because the IOPS went up by magnitudes. This is not a failure of the interviewees, who correctly went with the times, but a failure of the interviewers.

	▲	LPisGood an hour ago \| parent \| next [-]
		What kinds of system design questions got destroyed?
	▲	danenania 44 minutes ago \| parent \| prev [-]
		The correct answer is “Postgres would handle it, but if it needed to scale even higher, I’d…” The point of a system design interview is to have a discussion that examines possibilities and tradeoffs.