CLEAR Software Test Engineer interview questions

The question itself was relatively easy and focused on API testing, but the interviewer said specifically to use an array instead of a json object. This threw me for a while because the answer was to return a json object that did not have an array inside of it. I am still very confused by the interviewer saying to use an array and whether it was to get me to tell him it was a trick question. I also still wonder why they chose the specific library they did as it seems outdated.