An example of what you build on lpspec. A capacity-expansion planner: the model is 69 lines of YAML, the job that solves and archives it 380 lines of Python, this site 1225 lines of Markdown and SQL over the parquet the job wrote, and the notebook 342 lines. All of it is in the source; nothing else is behind it.

Where the numbers came from

Each archive records how every period terminated, what the model cost to build and solve, a digest of the spec it answered, and a digest of every input. So two runs can say which input differs between them without reading either one.

Which input differs

Each solve

What it cost

The model, as solved