There is a lot of discussion in the comments about using VMs for dev work. I too try to at least use containers whenever I can but it's sometimes not very practical. Better than nothing.

99% of the threat model is software trying to extract data. Either for myself (e.g. blackmail) or to learn about me and attack others (impersonation for scams, fraud, blackmail against others) or to access systems I have access to (tokens, API keys, online banking)

Currently I am playing around with local LLMs on a Mac. The whole field is moving so fast that it is impossible not to rely on recent releases to quickly try new features. Unfortunately there is no way to access the Mac GPU in VMs.

So right now to have at least a tiny bit of separation I have the local LLM tools set up on a separate local Mac user that I can then ssh into and use to expose a web server usable from my main (dev) account.

This of course is far from perfect but at least a little better than before. I fully expect supply chain attacks on AI tooling and perhaps even malicious LLM models to happen at some point. That target is too juicy.

Setting this up I was a bit irritated by some of the defaults of macos for multi user setups.

- All mac software is usually installed to the global /Applications folder. Homebrew needs a workaround to work across multiple users

- By default all files of a local mac user can be read by all other non admin local mac users. Only Apple-created folders like Documents, Desktop etc. are locked down

If you want to store files outside of those Apple-created folders, perhaps because you sync Documents with icloud and want to store project repos and larger files, perhaps because you have ssh and github configs, dotfiles etc. in your home dir, then they are all by default readable by other non admin users.

This is not to say that this is a huge issue that can't be fixed (just need to remove default permissions for group 'staff' yourself) but it is interesting that this is the default.

The concept of multiple local users seems to be completely ignored by users and by Apple, and has been mostly unchanged for decades. There are tiny improvements such as Apples permissions dialog when an application accesses Desktop, Documents or Downloads for the first time. But this seems pretty useless all things considered.

Why is it not more common to have stronger local separation? I don't need and don't want total iOS-level sandboxing (and lack of file system) but why isn't there a little more progress on the computer side of things?

I agree that VM-level isolation with good usability and little performance loss would be a great thing. But this is aiming for perfection in a world pressured by more and more supply chain attacks as well as more automated (read: AI controlled) computer use.

As an 80% "OS-native" solution it would be great if I could easily use local users for different project files _and_ stream GUIs across users (to work seamlessly from one main account). Then we could probably avoid the majority of security risks in every day computer use for developers and other "computer workers" alike.

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I skipped over that last part but this is the real blocker. It should be possible by now to easily stream a "remote" (local, different user) application UI into my current users window management with full support for my many screens, resolutions, copy/paste and shortcuts. All while having zero quality loss or performance overhead if done locally.

I don't want remote desktop, I want remote application UI. This is not a new idea (X11 forwarding)

Here's a fun thought:

AI workflows and agents have surprised us all. We see them clicking and typing and changing files on our machines. If the OS-makers don't come up with appropriate mechanisms then we will somehow end up recreating a new form of OS. It is already starting with AI-focussed browsers or ChatGPT as an entry point to delegate "browse the web for me". It will be web based with compute happening on VMs in the background, probably billed like a SaaS and disappoint all of us wanting to preserve the ideal of personal computers. Eventually it will make desktop OS's irrelevant and we all end up working with a form of chromebook