Hey, nice post!!
I really like the way you have described locks and concurrency. You have described lots of useful topics that every developer should know about but I think some topics not fully disclosed.
ReTest now has a Kickstarter campaign to make part of its tool open source and further foster Golden Master testing with an approach that has a few advantages on pure pixel-based comparison. Would love to get some feedback on that :-)
We at ReTest employ a similar approach — called difference testing — to compare changes against a golden master. Have a look at our tutorial if you are interested. Always happy to see others use golden master testing (and its derivatives) as well!
I’ve been writing code for the web since the late ‘90s. Looking back, I’ve come up with a few tidbits of experience I’d like to share with those considering the profession.