Wow, this is excellent! At a previous job, we had been using k8s + knative to spin up containers on demand, and likewise were unhappy with the delays. Spawner s

Wow, this is excellent! At a previous job, we had been using k8s + knative to spin up containers on demand, and likewise were unhappy with the delays. Spawner seems excellent. One question: have you had to do any custom container builds on demand, and if so, have you had to deal with large "kitchen sink" containers (e.g. a Python base image with a few larger packages installed from PyPI, plus some system packages like Postgres client)? We would run up against extremely long build image times using tools like kaniko, and caching would typically have only a limited benefit. I was experimenting using Nix to maybe solve some of these problems, but never got far enough to run a speed test, and then left the job before finishing. But it seems to me some sort of algorithm like Nixery uses (https://nixery.dev https://nixery.dev) to generate cacheable layers with completely repeatable builds and nothing extraneous would help. Maybe that's not a problem you had to solve, but if it is, I'd love your thoughts.