We replaced Docker with containerd on every node. What did we actually gain, and what runs underneath now?

Dockershim is gone and the CRI contract decides what a runtime must do. The senior-level part is the shim model: a supervisor process that owns exit codes and stdio so the daemon can die without taking workloads with it.

Grounded in researched DevOps, SRE and platform engineering interview loops, written to a senior-engineer editorial bar, and never padded to hit a word count.