The first interview question is always an RC filter.

It's an easy leading indicator of who has their shit together.

RC filter is like fizzbuzz for EE.

One of those is a basic building block used in pretty much everything, the other is software bullshit.

Looping through a list of items, and doing different operations based on their value is an extremely common occurrence, and you’d hard pressed to find a codebase that doesn’t use that pattern somewhere.

Welp, this is why interview fizzbuzz exists, because some people think of it as "software bullshit" instead of the simplest possible program you can imagine that should come out as fast as you can type it.

I feel attacked. I'm a DSP engineer and I haven't implemented an analog filter since I graduated. If we got into detail on RC filter gain and phase shift I'd fail. Do I have to give my EE degree back?

No, but you at least realize an analog filter is a thing that exists. You don't remember the specifics, but you could study them if you needed to.

As an EE you should know what goes in front of ADC to avoid aliasing.

I think it depends on what is meant by details. For a DSP engineer, if details are not knowing the difference between and RC made with ceramic or film cap, I’d give a pass there. If details are not solving continuous time equations in the form 1/s, that’s probably a fail.

or you buy a basic building block ADC and follow instructions.

Don't the software methods have very similar problems?

fizzbuzz is literally a filter, albeit digital, and it involces a circuit, well a loop in most realizations, too.

It's probably at the same level of complexity, give or take.

And, like fizzbuzz, lots of people fail it.

yep exactly, even with training and degrees and claims of competence