Selfhosted

Tailscale is great. You should use it. Most of their code is open-source. Their coordination server is closed-source, however there's a self-hostable open-source reimplemention called Headscale if you want a fully-open-source Tailscale stack.

Tailscale is a peer to peer VPN, meaning there's no central server like with OpenVPN. Systems on the VPN connect directly to each other. You can also use Wireguard in this way if you configure it as a mesh (every device on the VPN has every other device configured as a peer, and for each pair, at least one of them has the port open and forwarded). Tailscale is more reliable for that as it uses several NAT traversal techniques, so you don't need to open the port and it works even if both ends are behind NAT.

Immich doesn't rely on Tailscale; you can use any VPN. ~~They don't recommend exposing it to the public internet at the moment though, which is why you'd use a VPN~~ (edit: as per a reply, this is not the case any more). In general, never expose anything publicly unless it absolutely has to be (like a website that anyone can access). For giving access to friends, you can share a device with them via Tailscale and configure an ACL so they can only access particular services on it.

For the drives, I'd recommend ZFS instead of Ext4 or NTFS. ZFS can detect bitrot and corruption using checksums, which neither Ext4 nor NTFS can do. NTFS isn't recommended unless you're running Windows Server, but you already said you're using Proxmox.

IMO, use Syncthing instead of Nextcloud, unless you'll be using all the other apps that come with Nextcloud (calendar, office tools, chat, etc). Syncthing does one thing and it does it well, which is almost always better than using software that tries doing a large number of things. Consider Seafile too.

For backups, I'd recommend Borgbackup and Borgmatic. Get a cheap storage VPS to store it. You should be able to get a deal for less than $2/TB/month during the current Black Friday sales. Check LowEndTalk for deals. A Hetzner storage box would work great too.

To answer your first bit:

I went owncloud --> nextcloud --> syncthing + radicale.

Not looked back.

I run everything through a proxy in my home-built pfsense box.

I’m still learning myself, but am planning to use NetBird instead of Tailscale to access my VMs and apps without exposing them to the web. So far, it’s been pretty easy to set up.

I also had a lot of difficulty setting up NextCloud. Based on the various reviews and comments, it seems like I may have actually dodged a bullet.

In general, as I've tried different self-hosting solutions, I've found that using a dedicated solution for each purpose has given me better results. I use Radicale for contacts and Calendar, Immich for photos, Jellyfin for media (Navidrome for music is great, but I ended up keeping my music library in Jellyfin because I liked the client apps better).

I'm using OwnCloud for filesync, although I'm also testing CopyParty, which is pretty phenomenal and stupid simple.

Tailscale is GOAT. Some people have speculated that it could be subject to enshitification some day. It's managed by a for-profit company, but everything they do is open source. There are already well-tested forks like HeadScale if you ever have the need to self-host it in the future.

NextCloud seems great if you can get it working and provides a lot of services in one. Some people have said that causes bloat and slowdown, so there are two sides to the coin.

Syncthing is likely not a good option for a file server. It's great if you want to have a shared file or folder on multiple devices, especially if you just want to transfer files quickly and seamlessly. It's fantastic at what it does, but it's not a file server. There are a lot of opportunities for error when using Syncthing.

Syncthing. You don't need nextcloud.

I use wireguard directly instead of tailscale. Not sure what router you're using, but mikrotik support it out of the box. I am sure they are not the only ones. My phone runs on it 24/7 and has access to the rest of my services.

I haven't setup nextcloud, so can't give any advice on that. Immich was insanely easy to setup though.

I like navidrome, but I am not using jellyfin, so I have nothing to compare it with.

Id recommend setting up a domain even if just for local use. No-ip.com is at least working for me right now (i have free throwaway domain set up there and my router is keeping my dynamic ip dns records up to date so i can wireguard into my router/lan even if the ip changes).

You dont need to expose your services but if you ever do want to, it’s so much easier if youve got a working reverse proxy infront already set up plus you can use https via let’s encrypt certifications inside LAN

Setting up (sub)domains in lan forces you to learn to use a reverse proxy like caddy traefik or nginx. Personally to me NPM(nginx proxy manager) was the easiest to use but i use caddy nowadays. For half a year i didnt expose anything but after wanting to share some albums with the extended family i decided to do so via pangolin hardened with crowdsec running on a virtual private server. Pangolin - while not as easy as tailscale is selfhosted and is very well documented and works well. Then internally, i still have my casdy reverse proxy and certs.

All the services work with the same domain names internally (via the routers dns) and externally. Internally the domain simply points to my severs LAN address. Externally the domain points to my VPS where Pangolin relays my internal domains to the users but adds an extra authentication layer/recerseproxy/access control layer infront. For authentication i use Pocket ID. I can reach nextcloud and access and edit all my documents and other files right there in the browser from any computer which is very convinient.