Internals

How it works, for someone changing the code. What the code does for a user is the guide and the reference.

• Architecture — the pipeline, the tiers, the test contracts
• Testing — the test contracts each kind of change must satisfy
• Performance — profiling, and what a large model costs
• Design notes — how a subsystem was built, and against which normative reference
• Plans — the staged work behind a subsystem, kept for its rationale