You can try what Apple calls "fast user switching", which is actually pretty fast. The last (and only) time I used it, my days were split half-and-half between two projects for two clients, each with its own infrastructure. I did that primarily to help me focus but it had one pretty cool perk that I've been missing ever since: isolated accounts meant that I never had to worry about which Git/$SAAS/whatever user was currently authenticated and managing keys and such was a breeze as there was no "managing" needed, really.

I could do it because I had _some_ level of control on my work machine. Now that I work for a much larger organisation… I can't even imagine how hard it would be to have such a setup.

I don't know how usable it is in practice if you are switching contexts every 10 minutes, though.