AAA gaming is probably the worst possible example you can look at for what a well-run, sane team would look like. So let's say if you only want your people working 40ish hours a week and not 70-90, you'll 2x or 2.5x that count. Shopify also has a lot of dev rel folks even if they don't call them that - people writing engineering blog posts, working on tutorials, documentation, etc. They're typically not the same people actually working on core code day to day. My guess is all the infrastructure and security people at Shopify are non-devs. You'll also have all the devops people who are managing all the pipelines and everything. My understanding is Shopify deploys to prod many many times a day (hundreds?). The pipelines to automate that, and automate or at least manage the rollbacks, would be at least as complicated as the code itself. And across all these different areas you have that amorphous "Staff/Principal Engineer" level where you're doing a lot of reviewing, pseudo-management, that sort of thing. Not to mention managers, directors, VPs, SVPs, etc.

But you ask how they can productively use the time of 10k people and I think this post is sort of evidence that they couldn't.