On the Unhappiness of Software Developers (2017)
From the paper:<p><pre><code>  Freq  Cause
  186   Being stuck in problem solving
  152   Time pressure
  107   Bad code quality and coding practice
  71    Under-performing colleague 
  63    Feel inadequate with work
  60    Mundane or repetitive task
  57    Unexplained broken code
  42    Bad decision making 
  40    Imposed limitation on development 
  39    Personal issues</code></pre>