How D8Loop works: data pipelines
A five-minute guided tour · data pipelines
Build it. Get it reviewed. Defend it.
Most interview prep asks what you remember. D8Loop asks what you would decide — then checks it, and makes you defend it. You will make the calls on one real scenario, Daily orders ETL, on the same screens you will use.
About fifteen clicks, and every one is a decision. Follow the pointer — or use Back and Next in the guide.
Read the tour as text
- How D8Loop works — Build it. Get it reviewed. Defend it.. Most interview prep asks what you remember. D8Loop asks what you would decide, checks it, and makes you defend it. This tour walks one real scenario end to end on the same screens you will use.
- Step 1 · Read the brief — Every phrase in the brief is a requirement. A senior engineer reads a brief for what it rules out. Four phrases in this one each force something the pipeline has to get right: a daily cadence, a load that survives a re-sent file, a gate before publish, and a person told when it fails.
- Step 2 · The blank canvas — Now draw it. Where do you start?. The real canvas, with every component in the palette. Most people start dragging boxes here, and end up defending a diagram they cannot explain. D8Loop makes you understand the scenario first, in a directed way.
- Step 3 · Decide before you draw — Eight questions — three of them are yours. Eight questions, in the order an engineer asks them, each ending in something you will place on the canvas. Three are the real calls in this scenario — batch or streaming, what the gate does, and how the sink writes — and you make them.
- Step 4 · Your answers become the pipeline — Nothing is invented on the canvas. Each node is placed by the answer that asked for it, and your three calls are set on the nodes they decide. The canvas is a transcription of the spec, not a new idea.
- Step 5 · The reviewer reads your pipeline — Checks score it. You fix what they find.. Every check runs against the graph and every setting on it: the DAG itself, the scenario’s requirements, and reliability. The score comes from the checks, never from the AI. “Fix first” names the problem and the fix, and the weakest area links to the chapter that teaches it.
- Step 6 · Defend it — Now the interviewer pushes back. Four probes from this scenario, each graded on the points an interviewer listens for. A partial answer earns a follow-up, just like the room.
- That is the loop — Build. Review. Defend. Then do it again.. Everything in the tour runs on the real product: the canvas, the checks and the interview grading. In the studio, the answers are yours to write.