This is 100% wrong. Please ignore this answer.
Your work experience and education don't have to be in the same field. Your job as a Software Developer will count as a valid work experience as long as it is paid and NOC 0, A, or B. In fact, this is clearly stated by IRCC as follows:
Note: The applicant does not need to demonstrate that they meet the “employment requirements” listed in the NOC occupational description."
So, don't worry about your past education and choose the NOC code that matches you job duties and responsibilities as a Software Developer. Your application will be checked similar to any other applicant and you definitely will not be under "more thorough scrutiny and result is uncertain" just because your work experience is different from your education. Good Luck!
Source:
http://www.cic.gc.ca/english/resources/tools/perm/econ/fsw/minimum.asp