Your question is Reliable Batch Visualization Pipeline. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You are working on a visualization pipeline that pulls data from several upstream systems and loads it in batches. The data is used by dashboards and reports, so missing rows, duplicate loads, or late files quickly show up in the charts. The pipeline needs to stay correct when sources arrive at different times and when one batch is rerun.
How would you ensure a visualization pipeline is reliable when data arrives in batches from multiple sources?