Say hypothetically you want to pursue a certain area of CS and become proficient in it. I struggle when the PDFs run out, and I look to contribute to a Open Source project in the area however there seems to the chasm(obviously expected given I've only read an introduction on the topic effectively). It's bridging that chasm that I don't get. How do i go from writing Spark jobs to contributing to Spark?
> How do i go from writing Spark jobs to contributing to Spark?
What if you do the opposite? First try to contribute to Spark by picking the currently opened issues/bugs that looks the easiest. Write in the issue that you'd like to try to solve the issue but don't know the codebase very well, and that you might request some hand-holding if you have questions/get stuck. Most open source projects are willing to help contributors to get up to speed, so it could be a viable way.
As you start cranking through issues you'll learn more about the codebase and can stop getting help from others, maybe you'll start helping others instead.
When you're at this point (with a history of contributions) it'll be easy to find leads to jobs and also easy to get hired.