The 'cloud' (...which is a silly word...) runs on Nextcloud. Keeping it up doesn't cost much time at all, updates are close to painless for recent releases. I made a few apps related to library maintenance (OPDS Catalog) and reading (Reader, an epub/PDF/CBx reader)
Mail: Exim/Dovecot/Spamassassin/greylistd. Roundcube as a stand-alone web mail interface, not used much since Nextcloud gained a usable mail client. About 8 hrs per year of upkeep.
Web: nginx (used to use lighttpd) as frontend to a host of different applications and services running on two ancient Intel SS4200 servers. I'm about to move the whole bunch to a somewhat more upscale server (building a rack now to contain it plus some assorted network bits, disk cabinets and one of those SS4200's, the bottom bit of which will be used as a fruit/herbs drier so that heat won't go to waste...)
X2go to run X11 apps on remote locations
Searx for search, now also local search using Recoll and the mentioned plugin
GOGS for code hosting
I'm still running Trovebox as an image server, currently working on a media server to combine video, image and audio.
Subsonic/Madsonic for remote audio and limited video service, the same library is served by mpd on several machines in the network.
Some long-running experiments with XMPP (using Prosody) to use next to (and eventually replace) Telegram. If Telegram opens their server code this might not be necessary but I'm not holding my breath.
Eventually I'd like to end up with a plug-in replacement 'box' for many 'essential' network services, something which can run on modest hardware and does not take much upkeep so it can be used by as wide a range of people as possible. I'm not the first one, nor the only one to come up with this idea but as I've been doing this for more than 22 years now for personal and family use I do have some experience with the matter.