concept:as-of-joins
As Of Joins
As Of Joins in the context of production machine-learning systems.
Lessons
Formal explanations, examples, simulations, and checkpoints.
Data & feature foundations
Feature transformations that survive production
Ship the fitted representation contract with the model, in the same order and with the same edge cases.
Data & feature foundationsBatch, stream, and training-serving parity
Parity starts with one temporal meaning, then proves every execution path implements it.
Data & feature foundationsLabels, snapshots, and backfills
A label snapshot records what was knowable by a date, not the database’s latest opinion.
Courses & assignments
Dependency-authoritative learning units.
Casebook
Reported facts and course reconstructions.