I have to agree - it is possible to know if someone really just doesn't have a clue.

Case in point, this morning I interviewed a 'senior' C# .NET developer with over 10 years' experience - and yet she didn't even know the syntax for using lambda expressions, was barely able to get started with linq, and was unable to tackle a basic string splitting problem. Oh, and she couldn't do fizz-buzz.

"Senior" titles based on tenure length instead of actual skill & ability are one of the biggest problems in hiring. Only leads to pain on both sides. Perhaps we need different terms for these different dimensions.

How does that even happen? Those are things you use all the time in C#.. Maybe it's just working at a mediocre job(s) that never really stress skill?

Likely: She's been working at the same place for most of (if not all of those 10 years) and she's just basically keeping the home-grown system running and punching out some minor features. She probably got that Senior title simply because she'd put in enough time at the company. Maybe they're on .NET 4. Maybe.

If I see a technical candidate resume that has a long stretch (5+ years) at the same company and that company isn't primarily a technical one, huge red flags go up because the previously mentioned 'Senior' candidate is who generally come out of these situations. IF I get past their resume they're going to spend a lot more time telling me how they stay up to date with the world than a candidate otherwise would.

  If I see a technical candidate resume that has a long stretch (5+ years)
  at the same company and that company isn't primarily a technical one, 
  huge red flags go up

I'm a fan of this heuristic. You're forced to evolve more if you work in a profit center v. cost center (i.e. technical candidate at non-tech company).

I was interviewing for a position in India. Many developers in India (especially those that work for the big outsourcers) work on overly-large teams and work only on ridiculously specific portions of code. You might have one person that only does fluent mappings for the ORM, another that only makes changes to domain models, another that only does changes to view models... etc.

I do extremely basic programming tasks (no more difficult than fizz-buzz) to quickly weed out that sort of candidate.

Is that really skill? I work in IT and would like a development job but have never had one. I can easily pull off a fizz buzz in any lanuage I've worked with. Am I missing something?

No, it's not.

I was interviewing for a position in India; I just use such basic tests as a filter, so I can quickly weed out the wrong kind of candidate. See my other comment here for more: https://news.ycombinator.com/item?id=13327100

What you missed: You aren't interviewing for developer positions.

Is it different? I mean the fizz buzz I've seen only requires the use of conditional statements and a understanding of mathematical operators. What kind of programming job would leave you unfamiliar with those?

I'm saying if you're in IT, you can do fizzbuzz, and you want a development job but don't have one — then this all adds up to mean you haven't been applying for development jobs.

Ahh my mistake then. I have been applying but maybe not as much as I should have. I'll send out some more.

Send out more and fight with confidence to make them hire you. You're in the IT ghetto right now don't let their prejudices keep you there- you're every bit as smart and capable as anyone who happened to start on the developer track.

Fizz buzz is a trivial exercise; if someone that claims to have worked as a software developer can't do fizz buzz, something doesn't add up. How was she able to do her work without understanding basic things?

Getting fired after three weeks for incompetence simply doesn't happen at anything above junior levels. I've seen a few very quick firings up close and personal. On the junior level they really were incompetence, but usually mixed with a combination obvious personal issues (eg creepy around women) and work ethic problems. At the more senior level it was basically either borderline personality disorder (to generalize) or drug/alcohol addiction. It's almost impossible for a senior-ish person to be that incompetent if you're really being honest about it...we're talking three weeks here, not even months. I find it nonsensical that a relatively senior hire could be fired after three weeks simply for incompetence, there is likely a lie in here somewhere. Whether it's Snap or this fella, who knows, but I lean towards believing this guy.

Its unlikely/impossible that somebody that incompetent could get through the Snapchat interview process.

It's just hard to believe that such a person (with such low baseline) could come out of Facebook. Their interview process is quite thorough.

Also, interviewing aside, someone incompetent enough to get fired after 3 weeks at another company surely wouldn't last more than a couple quarters at FB.