A system you cannot hand over is not finished. If the only way to change it is to call the people who built it, you have bought a dependency, not software.

We write documentation as we build, not at the end when everyone has forgotten the details. It covers how the system is structured, how to deploy it, how to run it, and the decisions behind the parts that look strange for a reason.

At handover you get the repository, the infrastructure definitions, the environment setup and a runbook. A new engineer should be able to read it and make a safe change in their first week.

That is the test we hold ourselves to. If your team cannot own it without us, we have not done our job.