The flip side of this is that not everyone has the luxury of that much free time to focus on puzzle-type exercises just to get a foot in the door. This process seems to select for single people with a good amount of free time, which, depending on who you ask, is possibly what they want (if e.g. frequently greater than 40hr work weeks are expected).
Edit: thinking more about this, it's good to see that it's a paid puzzle, so even if you don't get an interview, you are still compensated for your time.
I understand your concern but you are actually talking from a privileged position. Its not really that hard to take a bit of time out of your evening or weekend to do some online programming exercise - IF that is the only thing that companies want. Anecdotally speaking I had to do these types of things while working full time to pay the bills.
Having a broader perspective - its maybe only in programming that the hiring process is so much easier. For almost any other job you need the right technical skills, years of expensive schooling, unpaid internships and have done a lot of networking ( cough nepotism cough ) - its only in programming that raw skills can get you anywhere.
> its only in programming that raw skills can get you anywhere
Simply not true. Maybe there's a few exceptions, but in general, most companies (especially in tech - just check out our great diversity :|), filter based on arbitrary things like 'school', 'specific # years of technical experience', and other flavours of the day.
Example: I had an interview with Mozilla many years ago, where the first question was, I kid you not, "Are you a Javascript rockstar?". I said no (being truthful - I was naive back then), to which the reply was an immediate "Sorry - bye".
> its only in programming that raw skills can get you anywhere.
The skill of programming is more like carpentry, mechanic, heavy machinery operation, or machining. I'm not going to higher a carpenter that can't tell the difference between a hammer and a saw, and I won't find a machinist useful if they can't run a lathe.
We need to start thinking of programming as a journeyman tradecraft career.
But that is exactly the strategy of the company. They want to select applicants that are young and have enough spare time to solve these puzzles. The fact that the puzzle is paid also makes sure that the small amount of cash is enticing for the applicants (i.e., young developers).
I don't believe that to be their strategy at all. It's a small company with a few devs who don't want to waste their time on junior/mid-level candidates. It's a prescreening process on both sides (me and the employer). I'm early thirties with a wife and two kids so it's not like I have dozens of hours to dedicate to that task.
Edit: thinking more about this, it's good to see that it's a paid puzzle, so even if you don't get an interview, you are still compensated for your time.