Scheduling software and EU data residency
Scheduling software and EU data residency: what hosted in the EU means when you host it yourself, and where the copies actually go.
scheduling software EU data residency is a procurement question wearing a technical costume. The person typing it has been asked where the appointment data lives, and they want a scheduling tool whose answer is short. This page is about what that answer looks like when you host the software yourself, and about the places the data quietly goes that nobody puts in the answer.
Nothing here is a ruling. Where your own data protection duties land is a question for you and your advisers, and no page in a software catalogue settles it. What a software catalogue can do is describe the mechanics honestly, which is what follows.
What hosted in the EU means when you are the host
With a rented service, residency is a claim about somebody else's infrastructure and you take it on their word plus their documentation. With a copy on your own server, residency stops being a claim and becomes a set of facts you can check, one per place a byte can land:
The application server. Whichever region you rented it in. You picked it and the invoice says so.
The database. Usually the same machine or the same provider. With Slotly it is MySQL, MariaDB or SQLite -- your instance, in your region.
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The backups. The one people forget. A nightly dump pushed to object storage in another continent moves the data there every night. Slotly's backups are taken from admin, as JSON with secrets redacted or the raw SQLite file, and where you put them afterwards is your decision to make deliberately.
The mail path. Reminders and confirmations go through your own SMTP server -- there is no relay in the middle and no sending service opening an account on your behalf. That means the mail route is whatever you configured, and it is worth knowing which country it is in.
The logs. Web server access logs hold IP addresses and URLs. They sit wherever your host puts them.
The page itself. A font, an analytics tag or a chat widget loaded from a third party turns every visitor into a request to that third party. A self-hosted booking page only does that if you add it.
The calendar feeds. This is the honest nuance most residency answers skip. A token-guarded read-only .ics feed is polled by whatever calendar the subscriber uses, so if a staff member subscribes with a consumer calendar account, that provider fetches the feed on their schedule. The feed is one way and revocable, and the choice of who subscribes is yours -- but it is a data flow, and it belongs in the answer.
What owning the copy changes
It changes the shape of the question from do I trust this vendor to do I know my own stack. The second is answerable on a single afternoon with a hosting invoice and a look at the cron file. It also removes the sub-processor chain: there is no vendor behind the vendor, because there is no vendor in the request path at all. Nothing in the software calls home, which is a property you can verify by reading the source you were shipped rather than a page that asserts it.
The same applies to the rota side of the same question. Rostera holds shift patterns and hours for the same staff, with its own token-guarded feeds and the same one-way rule, so a team that runs both keeps the two data sets in the same place and under the same answer.
The limits, stated plainly
Self-hosting is not a residency guarantee by itself -- it is a residency decision, and the decision can be made badly. A server in the right region with a backup bucket in the wrong one is still a cross-border flow. The hosting provider, the mail route and the log retention are all on you, and the software cannot know about them.
Slotly's own boundaries: it processes no cards, so there is no payment data at all; it runs one business per installation; calendar feeds run one way; anonymity and HTTPS are your server's job, not the application's. Rostera holds no pay rates and no attendance capture, so there is less personal data in it than most people expect.
Questions people ask
Does self-hosting on its own settle a residency question? No. It puts the decision in your hands rather than a vendor's, which is a different and usually better position, but the backups, the mail route and the logs are all part of the answer and all yours to place.
Does the software send anything to its author? No. Nothing in it phones home, there is no licence check that calls out, and you hold the complete source, so that is a claim you can read rather than accept.
Where do the reminder emails go through? Your own SMTP server. There is no relay, no sending service and no account opened for you, so the mail path is exactly the one you configured.
Where to look next
The product pages are Slotly for appointments and Rostera for the rota, each listing what it stores and what it deliberately does not. The side-by-side sets the appointment half against the hosted services, and the scheduling alternatives page is one common starting point. A companion page in this series takes the same subject from the other end: the residency questions to put to any vendor, whoever is hosting. For what the rented alternatives charge, read the observatory: each figure is quoted verbatim beside the date it was read and a link to the vendor page it came from. Prices are on the observatory; read them on the date shown there.