Docker and similar, on a VPS.
WHAT THEY DO
Package an application with its dependencies so it runs identically anywhere, isolated from other applications on the same host.
THE ADVANTAGES
Consistent environments between development and production Isolation between applications Easy to run several versions of the same software Reproducible deployment
THE COSTS
Another layer to learn and maintain Container images need updating for security, as much as packages do Persistent data, networking and backups need deliberate handling Debugging is less direct
WHEN THEY HELP
Multiple applications with conflicting dependencies A development team wanting environment parity Applications distributed as container images
WHEN THEY DO NOT
A single WordPress site. The complexity buys nothing.
THE COMMON MISTAKE
Treating containers as a security boundary equivalent to separate machines. They are isolation, not a guarantee.
A PRACTICAL NOTE
Containers running on an unpatched host are not secure. The host still needs the same maintenance.
