If his goal is to guarantee a reasonable (actually very low) developer salary this feels like bad advice. There is no guarantee he will get hired, no backup plan if the project does not hire him, and he could very well walk away with nothing.
If your goal is to get a job just look at trends in job boards (probably very skewed towards web/mobile/data science), figure out which area you like/excel in and hone in on that. Keep iterating on your resume, upping your skill set, and learning from interview failures. Remember: selling yourself and your skill set is more important than actual ability. That is something you can really only hone with practice and repeated interviews.
If your goal is to get a job just look at trends in job boards (probably very skewed towards web/mobile/data science), figure out which area you like/excel in and hone in on that. Keep iterating on your resume, upping your skill set, and learning from interview failures. Remember: selling yourself and your skill set is more important than actual ability. That is something you can really only hone with practice and repeated interviews.