Data
PostgreSQL for application data, Redis for shared state and coordination, and MinIO for object storage across its public, protected, and chat buckets.
Operating model
Mirket is an on-premise-first system delivered as a composed stack. This is what you are taking on, described plainly, so the decision is made before the install rather than during it.

One composed deployment per facility.
PostgreSQL for application data, Redis for shared state and coordination, and MinIO for object storage across its public, protected, and chat buckets.
The API, a socket service for realtime, background workers, and the three role applications for students, instructors, and administrators.
A Matrix homeserver for chat, LiveKit with its egress companion for live sessions and recording, and a document service for in-place editing.
An edge service fronts the role origins, and a CDN service delivers assets. Migrations run as their own step rather than on application boot.
Backup and restore are scripted operations with a rehearsed drill, not a runbook paragraph. The restore path is exercised on a schedule so the first real test is not the one that matters.
Someone at your institution needs to be comfortable running containers, holding backups, and applying upgrades on a schedule. That is the honest cost of an installation nobody else can reach into. If that is not a fit, the hosted licence exists for exactly this reason.
The manual covers this as a task, with prerequisites, what finishing looks like, and what to do when it does not work.
Run it on your own infrastructure or let us host it for you. Both licences ship the same product; the difference is who operates the data plane.