I have never used the Instagram API and had to look up what a tagcloud is just now. I can immediately say this will take more than 'a couple of hours', whenever I work with a new API it takes time to setup the environment, digest how it works and research the appropriate APIs I need to use. I am not surprised by your experience. Actually makes me angry that someone thinks a reasonable person could do that in two hours with the background I have described. Yes two hours is the environment is setup to make calls to the API and perhaps you have some familiarity with it - so I can see why the person who asked the question would think 'I could do it in two hours, on my Macbook where the environment is already set up and where I know exactly what API is required and what the data format looks like in the response'.

This seems to happen on around 50% of the take home tests that I have been given. Funnily enough I only take the time to do 50% of them.

Hackerrank is even worse. They have strange ways of wording the questions. I have to Google around to work out how to use their input and output (I work with databases all day long, not reading and writing to STDIN/ STDOUT). No step through debugger (which makes a lot of sense for the algorithmic type questions they ask). Cut and paste only works in some browsers.

No one expects you to set up a database and connect to it in that sort of timeframe - yet I would probably manage it better as I do it regularly.

My personal favorite, was when, after I had apparently survived a 4-hour interviewing + whiteboarding stint, and thought I'd be able to head out onto the street (as it was already quite late in the day)....

...a math PhD told me "hey, I got one more ya..." and proceeded to give me a mis-articulated mathematical search problem which -- going by his own statement of the problem, ended up having as its "solution" -- an empty class.