Design Pattern · September 2026
Packet workers before execution workers
An execution worker changes live state. A packet worker only produces something a person reviews. Start at the bottom and climb only when review has become boring.
Under the pillar Zero Neo
The ladder
The safety question is not whether the model is good. It is what happens in the world when the model is wrong.
The distinction
A packet worker assembles: it gathers the records, checks the eligibility, drafts the letter, and hands a person a decision-ready package. If it is wrong, a person notices before anything moves.
An execution worker acts: it books, sends, updates, closes, and pays. If it is wrong, the error is already in the world and the correction is a second piece of work.
Both are useful. The mistake is deploying the second when the first has not been run long enough to know the error rate.
The promotion rule
A worker earns the next rung when a reviewer has seen enough of its output that reviewing it has stopped being interesting, and the exceptions it produces are the ones the reviewer would also have flagged.
That is a deliberately unglamorous criterion. It is also measurable, which the alternatives are not.