I had a 4-hour assignment requiring a full weekend (10 medium to difficult queries on an unknown 20 table database and document with business analysis for the query results + additional code to extract from api and save to db with your own schema + additional queries on top of this).

I also had an 1-hour where i couldn't build the provided code and had to go through maven repos and older versions of the major test component to make it work after a couple hours and then lost any motivation to write the simple exercise.

I also had an honest one once, where the instructions were clear, you will need a full weekend to do it. I liked the job and i completed it, only to be rejected because they didn't like my scala syntax.

Sorry, but i won't take home test again and have to gamble whether it's an actual 1h test or a full weekend one, or some random guy will spend 1 minute only to reject me.

Yeah it doesn't matter. The truth is that when you give an assignment like this, you want me to invest up to four hours in it, while you don't want to invest a single minute of company engineer time watching me solve it. Basically, you're expecting more of me than you are willing to give yourself. That's a huge red flag.

That being said, even if it takes an hour, I still have to allocate 4 hours for it.

I had one take-home "4 hour" assignment that required me to install two different, poorly documented, third party packages on my computer before I could even begin to write the code. The Java-loaded piece of junk that I needed didn't work with my existing setup, and I wasn't going to rebuild my entire system just for some arbitrary assignment. It might have been "4 hours" if I already had an environment with all the extra cruft that they used, but if I had to fart with VMs or rebuild my machine? No, just no.

It's reasonable to expect someone have various languages on their personal boxen, and maybe git, but not repositories, specialized third party tools, etc. I don't run Puppet at home, for example.

I actually asked a company that had already offered me a position recently if they had a technical test. The one they sent me was clearly stated and it was easy to configure everything needed. If it had been otherwise I very likely wouldn't have accepted the offer.

In my experience a (not timeboxed) 4 hours coding assignment will actually take at least a day.

Is not necessary malicious from those companies, they just underestimate the time their test take.

IMO, most engineers massively under-estimate the time it takes to do "simple" tasks if you don't already have the infrastructure/environment set up for it.

And some times they assume specific or latest versions of some platform because they are currently working on it. I remember some flink take home required some latest api, while i have worked with flink in earlier versions. It took me 4h just to go through the updated documentation, while it was supposed to be an 1h one.

This is why I prefer in person coding exercises. You can do 1-1.5 hours of a "4 hour timeboxed coding assignment" and the interviewer will usually be happy that theyve seen enough and that you're not too slow coz they watched you do it.

Thats 3-8 hours of your life back.

This must depend a lot on the place.

I did a data science take-home that asked you to scrape some documents from the web, group them by topic, extract some information the clusters, and visualize it. This could be a few hours of work, or an entire research career.

IMO, a good take-home needs to be aggressively scoped. Ideally, I think you'd explicitly ask for --and expect--a "bare minimum" solution and a list of potential improvements. That list would be great fodder for in-person interviews too.