Landlock is the security sandboxing feature available since Linux 5.13. Its goal is to empower developers by letting them harden their applications. Indeed, it is assumed that with enough skill and time, most of software could be compromised. Sandboxing enables to add a new layer of security to mitigate such attack. This talk quickly introduce the main Landlock properties, and we then explain how to sandbox your own application. We'll use p7zip, a C++ archive manager, as a practical example.