You cannot possibly know if a technical employee (at this level) is incompetent after just 3 weeks. Not possible.
It's the same as firing a CEO 3 weeks into the job... It doesn't make any sense unless that CEO did something blatantly illegal/dodgy during those 3 weeks.
The reality is you won't know how good they are until at least 6 months in.
As an engineer, 3 months is the absolute minimum amount of time I need to figure out if I'm a good match for a company.
You may be assuming a baseline competence, though.
I've interviewed many alleged senior developers who talk a good talk, can tell you the full ASP.Net page lifecycle without missing a beat - despite (possibly sometimes in spite of) not being asked - and when it comes to actually coding show their utter incompetence in seconds flat.
I'm not being elitist here; they'll do stuff that's just plain weird, like only using strings in C# - no other datatypes, only strings - or if they claim database expertise, create tables with only text columns, no indexes, and storing an integer primary key also as a text field.
At any ability level above this, I'm kinda with you; just take into account there is a very real world of sheer utter incompetence out there, and I doubt it's limited to technical employees.
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.
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 do extremely basic programming tasks (no more difficult than fizz-buzz) to quickly weed out that sort of candidate.
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
There are certainly major failures possible in 3 weeks for which the optimistic explanation is gross incompetence, and the pessimistic one is gross misconduct.
Source: https://www.totaljobs.com/careers-advice/money-and-legal/ref...
still I have seen developers gone in a weeks time, some voluntarily
I would summarize the complaint as:
Snapchat hired this guy from Facebook. He claims Snapchat falsely represented their growth during the process (two metrics which are redacted turned out to be false.) After he joined, he alerted the VP of finance that some of Snapchat's representations were false, who apparently agreed with some of it and told their VP of Comms to stop representing that to advertisers and some redacted group. He thinks that Snapchat fired him because of this, that they thought he would "blow the whistle" on upcoming IPO. Further, Snapchat continually pressured him to breach his confidentiality agreements with Facebook. After he was fired, Snapchat told people internally and externally that he was incompetent.
In the details, a lot is redacted but it mentions there were specific metrics given to him in the hiring process - that were also given while raising capital in Asia - that were false.
According to the complaint from Anthony Pompliano: When they were trying to hire him Snapchat said they would hire 40 people under Pompliano for his growth team. Based on this promise he left FB to join Snapchat. He then found the numbers they were touting were not accurate and they were not committed to what they told him.
When the complaint gets to what happened starting the day Pompliano was hired and more specifically what happened when working there, it is blacked out for the next 8 pages.
After those pages it says he was fired after 3 weeks and Snapchat told employees, media contacts, and a company looking to hire Pompliano he was fired for being incompetent. This misrepresentation has cost him his reputation, money, etc.