Virtualization, continuity and systems for remote sites
A mill in the forest or an office thousands of kilometers away can't rely on internet uptime to operate. I set up local infrastructure that keeps working when the link drops and syncs back up when it returns.
Installation and administration of Proxmox environments: virtual machines, containers, service isolation, and making the most of existing hardware instead of buying a server per application. Open source, with no per-socket licensing or billing surprises.
Many companies are still running unsupported versions, with no security updates and no recovery plan. I've worked with environments like that in production, migrating critical services — accounting, payroll, domain controller, antivirus — to updated platforms without interrupting business operations.
Automated, off-site, verified backups. A backup that's never been restored isn't a backup: checking that recovery actually works before you need it is part of the job.
Linux servers (Debian, Ubuntu), nginx and Apache, MariaDB and MySQL databases, certificates, firewalls, monitoring and security hardening. Remote administration, with on-site visits when needed.