Cutting a lesson down — Monitoring data, not just jobs

A note from writing Monitoring data, not just jobs, which took three passes to get to something short.

Job monitoring tells you the code ran. Data monitoring tells you the numbers are right. Teams that only have the first find out about the second from a stakeholder.

The hard part of writing this was cutting it. The first version covered every case; the useful version covers the case you hit on a Tuesday and names the rest in a sentence. Completeness is a property of reference material, not of teaching material, and confusing the two produces something nobody finishes.

It sits in the Shipping it and keeping it alive module. The exercise is a thinking one rather than a query one — some of this material is about deciding what to compute, and that does not need a keyboard.

Ordering matters here more than in most courses. It follows Orchestration, and what "it runs every night" costs and leads into Owning something that runs without you, and reading it out of sequence mostly works but costs you the setup.

Free means free, and it also means we can rewrite it whenever it is wrong. No edition, no errata PDF, nothing to repurchase. The whole course is 36 lessons and the fixes land the day we find them.