I've gone back and forth between them, but it helps that I have a Physics PhD so I am not intimidated by the math.I got my PhD in 1998, did a postdoc in Germany for a year, came back to the states, started doing remote work and consulting projects for web sites, worked on the arXiv preprint server for a few years, then worked on a pretty wide range of projects for pay and for side projects until I got interested in using automation to make large image collections on my own account circa 2008 ...