Read this blog post on Medium.
In 2012, at the age of 24, I "dropped out" (left with a master's) of a Ph.D. program in evolutionary biology at The University of Chicago after deciding I wasn’t entirely comfortable with the limited (and highly competitive) career opportunities in the field. Having always been a fan of computers and technology (and being encouraged by the booming job market), I decided to explore my options in computer science. After some investigation and introspection, I came to the conclusion that a career in artificial intelligence/machine learning would be the perfect fit for me.
In the fall of 2012 (when I was turning 25), I applied to five different computer science M.S. programs (UT Arlington, UT Austin, UT Dallas, Texas A&M, and Texas State) with the hopes that my limited (ahem, non-existent—I literally had zero programming experience prior to the summer of 2012) computer science background would be somewhat offset by my exceptional academic history. I was denied admission to every program except UT Dallas.
In the fall of 2013 (when I was turning 26), I began my studies at UT Dallas, choosing the "Intelligent Systems" track, which included coursework in artificial intelligence, machine learning, statistics/graphical models, deep learning, statistical relational learning, and natural language processing, among others. I busted my ass my first semester, taking four classes (which required special permission) to make up for the fact that I didn’t have any of the prerequisites (again, because I didn’t have any computer science background).
In December and January of that school year, I started applying for internships. I ended up getting a part-time "research internship" in a bioinformatics lab at UTSW for the spring semester, and was then offered a summer (2014) position as a "Software Engineering - Data Science Intern" at Red Hat. I wound up doing some interesting work at Red Hat, which resulted in them allowing me to continue my internship part-time and remotely through the second year of my master’s. I graduated from UT Dallas this past May and joined Red Hat as a full-time "Software Engineer" in June, where my first six months of work have been heavily data science/machine learning-focused. I'm currently 28.
I should note that, once I dropped out of UChicago in 2012, I became actively involved in self-education, and had already developed a couple of data-oriented applications (that I put on my GitHub), taken several MOOCs, and even made a small contribution to CyanogenMod by the time I enrolled at UT Dallas. So I was never really idling.