Create a hierarchical taxonomy using excel sheet of different software development skills. There has to be a skill hierarchy with broad things like front-end, back-end initially and then more specialized skills/technologies in each. Approximately 200 leaf level nodes could be great. We want to ultimately map each software developer into scores for different skill/interests.
Example: Language -> Java-> Angular/ Node/ Ajax, etc.
Generally focus on skills/technologies that are either relevant to many jobs (eg: PhP, MySQL) or relevant to a few jobs that are very hot and high paying (AR, Machine Learning).