Anecdata incoming: a company I worked for had such a referral. They bombed the interview. The referring employee was incredulous. I was asked to re-interview them. They did seem good, they got an offer. The experience delayed things, put a bad taste in the candidates mouth, they took a different offer.

My point, the result of interviewing a good developer is potentially random. There is perhaps less probability of a bad developer having a random outcome as well, but certainly can happen.

Though.. define "good". Some people are incredible only when in the right team and environment.

I have seen a few situations like this:

Company says "looking for an expert on X"

Expert on X walks into the room.

Interviewer: "How good are you at Y?"

Expert on X: "I know a little about Y, but not too much. I mostly use X for my work; I could show you how to solve the problem using X."

Interviewer: "Thank you for your time; goodbye."

When I tried to figure out why this happens, the answers are usually something stupid like: "HR posted the job announcement, they have no idea what we really need", or "yeah, we are still looking for an expert on X, but we need an expert on Y more urgently". (The latter still does not explain why they rejected the expert on X without asking him anything about X, but to the person who said this it seemed to make perfect sense.)

I think the parent commenter was asking from the point of view of a person looking to be employed, not a business or hiring manager looking for devs.

None of the FAANGs or even tier 2 companies work on references, unless you invented the internet or something.

And even then, there is a famous story of the dev of the popular MacOS FOSS package manager, Homebrew, failing his interview at Apple.

I don't get the point why a maintainer of a popular package failed his interview. Having a popular package has nothing to do with coding ability and much more to do with writing the right thing at the right time.

He wasn't the "maintainer of a popular package".

He was the creator/designer and main dev of Homebrew, the OSS <<package manager>> almost every dev on MacOS uses.

He took an idea to completion, made it production ready and used by probably millions of users.

I don't care about raw coding ability (Carmack style), if building such a large project doesn't prove at least development abilities, nothing does.