[PragmaticPulp]

> I have never in my career had to do anything like designing a large scale system.

Giving large scale system design interview questions for a role where someone never has to work with large scale systems would be a weird cargo cult choice.

However, when a job involves working with large scale systems, it's important to understand the bigger picture even if you're never going to be the one designing the entire thing from scratch. Knowing why decisions were made and the context within which you're operating is important for being able to make good decisions.

> I've worked with the Linux kernel, I've written device drivers, I've programed in everything from Fortran to Go, and that's what I want to keep doing. Why put me through this?

If you were applying to a job for Linux kernel development, device driver development, and Fortran then I wouldn't expect your interviewers to ask about large scale distributed web development either. However, if you're applying to a job that involves doing large scale web development, then your experience writing Linux kernel code and device drivers obviously isn't a substitute for understanding these large scale system design questions.

[taeric]

Oddly, knowing the limitations of last year's designs can, as often, limit you to last year's solutions. That is to say, the reason things were done in the past almost always come down to resourcing constraints.

Yes, it is good to understand constraints. It is also incredibly valuable to be respectful of the constraints that folks were working on before you got there. Even better to be mindful of the constraints you are working on today, as well. With an eye for constraints coming down the line.

But, evidence is absurdly clear that large systems are grown far more effectively than they are designed. My witticism in the past that none of the large companies were built with the architectures that we seem to claim are required for growth and success. Worse, many of them were actively done with derision for "best practices" coming from larger companies. Consider, do you know all of the design choices and reasons behind such things as the old Java GlassFish server?

Even more amusing, is to watch the slow tread of JSON down the path that was already covered by XML. In particular the attempts at schemas and namespaces.

[jjoonathan]

> large systems are grown far more effectively than they are designed

It's easy to bake in poorly scaling technical decisions at an early stage that take an obscene amount of engineering effort to undo once the scaling problem become obvious. I've seen intern-days of "savings" turn into senior-years of rework and the scale in my corner of the world is tiny by SV standards.

I always assumed that SV companies experienced similar traumatic misadventures, multiplied up by scale, and baked "thinking at scale" into their technical interviews as a crude (but probably somewhat effective) countermeasure. Even if you only ever use the knowledge one time, indirectly and accidentally, by peer-pressuring your buddy into thinking before coding and therefore avoid a $10M landmine, it was all worthwhile.

[thrashh]

To me this is a entirely separate problem.

I’ve noticed that when less experienced people try to solve a problem, they have to look up how other people do it first.

But someone more experienced has a strong understanding of technologies on an abstract level so they can whiteboard a solution without even involving any specific software (then compare to how others do it). When you think that way, you’re not worrying about JSON or XML. You become neither tied to last year’s tech or too eager to try new tech. You just build something solid that’s reliable and long-lasting.

Knowing about different tech used in different designs expands the pool of legos that you can snap together and so it can’t hurt.

[lisasays]

You missed the key statement in the commenter's post:

"If that's a requirement just say so"

Clearly the roles they're applying for are not concerned with the ab initio design of large-scale systems. Which is why they said what they said. They're not whining for the sake of whining.

Your experience writing Linux kernel code and device drivers obviously isn't a substitute for understanding these large scale system design questions.

A drop-in substitute, no. But an engineer who has the wherewithal to truly master the grisly low-level stuff can easily ramp up reasonably quickly in the large scale stuff as well, if needed. To not understand this is to not understand what makes good engineers tick.

We get the fact that, yeah, sometimes, for certain roles a certain level of battle-tested skills are needed in any domain. Nonetheless, there's an epidemic of overtesting (from everything to algorithms, to system design, to "culture fit") coursing through the industry's veins at present. Combined with a curious (and sometimes outright bizarre) inability of these companies to think about what's truly required for the roles -- and to explain in simple, plain English terms what these requirements are in the job description, and to design the interview process accordingly.

[nineplay]

The problem is that the system design interview somehow became a necessary component of the FAANG hiring process.

[SpicyLemonZest]

FAANG and similar companies typically subscribe to something like the "T shaped engineer" philosophy. They're making a conscious choice that their engineers should be comfortable in discussions about distributed systems, performance tradeoffs, etc. regardless of whether they do such things on a regular basis.

[duckfruit]

Certainly not at the FAANG I work at. We hire specialized engineers to work on device drivers and OS kernels and absolutely do not ask them questions on how to design distributed web services.

I encourage you to apply: https://www.apple.com/careers/us/

[Zetice]

Why would you interview for a role at a FAANG company in the first place?

[greiskul]

My understanding is that this is not the case any more for the more junior software engineer positions in Google and in Amazon, which are expected to them learn system design before being promoted. If you are applying to a more senior position, then yes, there should be a question about system design, and yes, you will probably be doing system design in your work, so it's completely fair game.

[babyshake]

And the second part of this is that just as all non-rich people tend to consider themselves as soon to be millionaires temporarily down on their luck, most startups (especially the VC funded ones making big promises to investors) tend to consider themselves soon to be FAANGs temporarily in the early phase of their inevitable hockey stick growth.

[zoover2020]

Is this a problem? I would argue that this style of interviewing is much more relastic to day-to-day activities than leetcode

[heisenbit]

I have really good analytical skills which I leverage to tackle issues in large scale system piecewise. I have to suspend my skeptical mind and switch to blue hat thinking to come up with something from scratch. Then I take it apart and iterate over it. I don't think large scale system design is a straightforward process and pretending it is so may very well lead to living in interesting times.