An important distinction that's missing in this discussion is that you can be either an SA-SRE or a SWE-SRE. You can figure out which is which from how the SRE

An important distinction that's missing in this discussion is that you can be either an SA-SRE or a SWE-SRE. You can figure out which is which from how the SRE job postings on google.com are phrased. SWE-SREs have to pass SWE interviews. I work down the hall from Tim. Nobody keeps track of who came in through which side (SA or SWE), but some of the SREs I work with wrote large parts of the services they support.