An inherited pipeline, mapped stage by stage

You inherit a pipeline with no documentation, and the person who understood it just left.

Beginner to intermediateRead 7 minDoing: half a day, more if the run history goes back further than expected7 steps

▶ Start

What you'll have at the end

A one-page map of every stage the pipeline touches, with the biggest unmonitored gap circled

Before you start

You need

A pipeline you now own, with access to its code, its schedule, and its recent run history, but no documentation and nobody left who can explain it.

Not covered

This does not cover writing the on-call runbook or adding new tests and alerts once the gap is found; it only covers building the map that shows you where to aim those next.

Leans on

Find out what actually makes up the pipeline

List every artifact that touches it
Chain stages by what they read and write
Check what each stage really does

Find the part nobody's watching

Mark what's watching each stage
Find the stage nobody would notice

Turn it into a map, and test it

Draw the one-page map
Test the map against a real answer

Where to go next

Write an on-call runbook for the pipeline only you know how to fix

for turning the map's circled gap into the runbook and alerts that actually watch it

Checked 26 Aug 2026

Part of the Data Engineering Core cookbook