Software Engineering at Google (2017)
I was the maintainer of a third-party library used by thousands of dependent applications at Google.  I have to admit, I still have not seen on the outside a system that allows me to change the version of numpy, and know that thousands of dependent applications either work or break, within an hour of making my change.<p>Being able to write and use a mapreduce with a high level of confidence that my code would continue to work years later was another nice benefit.  MRs I wrote in the first year at Google still compiled and ran with minimal changes almost 10 years later(!) which is amazing given the amount of environmental change that occurred.<p>That said, somebody could still halt development across the company by changing and checking in a core file (like proto defs for websearch) without testing.<p>Whatever social system led to google3&#x2F;borg and the amazing productivity associated with it, it was a special moment that hasn&#x27;t been replicated many times.