u/Aecision

I am looking for zero-knowledge, open-source software that functions similar to Google Drive. I've looked around and even tried some based on what I've found here and from other sources, but I haven't found a solution that just feels right to me.

Products I've tried:

• NextCloud: Didn't like the bloatware and annoying E2EE encryption extension/abilities (from my memory, I tried this probably ~8-ish months ago).
• Seafile: Initially I really liked it, but the client app is a bitch to work with and you're essentially SOL if something specific to the software isn't working as intended and hasn't been mentioned in the documentation. Also, I'm not fond of the service gating many of the security features behind the "pro" version of the software ($100/y) even when selfhosted. Essentially, the lack of intuitiveness of many of the core functions of this product (ranging from normal use to managing the software) have soured my view towards it.

I'm looking for software that:

• Has support for multi-device E2EE (for example, what Signal does). Apps offering other means of zero knowledge architecture can be acceptable.
• Has a client app for, at a minimum, Windows (ideally iOS/macOS though). I could create my own client for otherwise-perfect software, but I'd really rather not.
• Open source and actively developed. Ideally free to selfhost, but I wouldn't mind paying a one time fee for better features if the best software requires it.
• Significant bonus points if the UI doesn't look terrible.

Context
I am a university student, about to go to graduate school, who does this for:

• a fun hobby
• hosting my random dev creations/open source projects I find and like
• reducing my reliance on big tech/increasing privacy.

I currently rent a dedicated server running Ubuntu for a really good price, along with a killer deal I got for storing my data in a (reasonably) private way. My infrastructure is solid to the point where I'm less worried about software impacting performance, but ideally it would be lightweight relative to the functionality. I'm aware this isn't selfhosting in the fundamentalist sense, but it is the best solution for me given my lack of "adult" job money and stable housing (as in, I don't know how often I'll be moving over the next few years; I'm not at risk of becoming homeless). I fully plan on making one of the coolest server rooms to grace this subreddit in the future, that is just not feasible for me right now.

I understand that some people don't mind "good enough" privacy in the software they use, and I can respect that perspective given it is usually already a privacy win to selfhost at all. However, that is not what I am looking for. Given that my hardware is remotely controlled, I want a zero knowledge solution to function on top of the security infrastructure I have in place. In a hypothetical nightmare scenario where someone has full access to both my data storage provider and my server at the same time, I want to rest comfortably knowing that my documents are essentially useless. This may seem like overkill, but that's what I'm looking for.

I'd also probably integrate this service through Twingate for an even greater level of access control. However, that's less relevant to my overall request as that layer is pretty much agnostic to whatever I decide to use.

My request

I'd greatly appreciate being pointed in the right direction for what software I could use to achieve my desired result. If what you have doesn't apply, but you loved it, feel free to share regardless; maybe it'll be applicable in some way.

Thank you!