Decomposing the Prompt

Concepts: paEltVsEtl, paDagOrchestration

When an interviewer says "design a pipeline to ingest clickstream data from our mobile app into our analytics warehouse," they are not asking you to start writing Spark code. They're asking: can you think in layers? The single biggest mistake candidates make is diving into implementation before establishing scope. The Five-Layer Framework Every pipeline decomposes into five layers. Naming them explicitly in the first 60 seconds of your answer signals seniority. Say: "I'll walk through this in five parts: ingestion, transformation, serving, orchestration, and quality." Then pause. Let the interviewer redirect if they want depth on a specific layer. You've just demonstrated that you see the whole system, not just the Spark job. Clarifying Questions That Show Seniority Before designing anythi