Data Observability

Pipeline health is not data health. Freshness, volume, schema and quality as monitored signals, and the upstream walk that turns "revenue looks wrong" into a cause.

Data Observability

Pipeline health and data health are two different systems. A platform that watches only the first finds almost none of the incidents anyone cares about.

Q · Every task has been green for a month and finance says the quarter is wrong. What should have been watching, and what was it watching instead?
Pipeline Observability

What an orchestrator genuinely knows, what it structurally cannot know, and how to make a task-level signal say something about data.

Q · The DAG is green. Precisely which claims about my data does that entitle me to make?
Pipeline Metrics

Rows processed, bytes processed, duration, failures, retries and lag — what each one detects, what moves it for boring reasons, and what none of them can see.

Q · Which six numbers, recorded per run, would let me tell a broken pipeline from a busy one without opening a log?
Freshness Monitoring

Freshness is a per-dataset property. Averaging it across a platform hides the one table that has not updated since Friday — and the false-positive rate decides whether anyone still reads the alert in six months.

Q · How old is the newest complete record in this dataset, and how old is it allowed to get before someone should be told?
Volume Anomalies

Comparing today with the same weekday historically is the cheapest broad detector there is — and it misses every error that preserves row count, which is most value-level bugs.

Q · Does the number of rows that arrived today look like the number that normally arrives on a day like today?
Data Incidents

A dashboard says revenue dropped eighty percent overnight. Seven different causes produce that symptom, and telling them apart is the job.

Q · Revenue on the executive dashboard is down eighty percent since yesterday. Before touching anything, what could produce exactly that symptom?
Debugging a Data Incident
▶ lab

Consumer symptom to serving dataset to transformation to upstream dataset to ingestion to source. Debug upstream, always — and diagnose from the set of checks that failed, not from the first one.

Q · The number is confirmed wrong. What is the sequence of questions that turns that into a cause, and in which direction do I walk?
Lineage Debugging
▶ lab

Click a dashboard metric and walk it back — tile, metric definition, mart, model, staging, raw, change capture, production database — then turn around and ask what else this feeds.

Q · Where did this number come from, and if the table behind it is wrong, what else is wrong right now?