We gave the estimation as follows: - Junior developers should be able to finish this within a work day (8 hours) - If you are already familiar with all technol

We gave the estimation as follows: - Junior developers should be able to finish this within a work day (8 hours) - If you are already familiar with all technologies involved then it should take about 2 hours even with all optional tasks completed. As an example our backend dev task was to parse a CSV file (supplied with the task) and provide 2 API endpoints (return format and url defined in the task) that access this data (free choice in language and libraries). The optional tasks for this was to include unittests and to use docker. That really isn't much work. We did get some good feedback about this estimate both from junior developers and seniors after they were hired or rejected. Most seniors seem to complete this task in about 1.5h to 3h and juniors do seem to be able to complete this in about 6h.