{"blocks": [{"key": "46c28a40", "text": "Scenario", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "6c1d387c", "text": "Instagram is launching a short-video recommender feed.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "ea7f553f", "text": "Question", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "d0f1ad1e", "text": "a) Which single metric would you use to evaluate the recommendation system’s success and why?", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "362de511", "text": "b) Sketch or describe the expected distribution of that metric, labelling median, mode, and 95th percentile.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "850f91d4", "text": "c) Metric A rises while Metric B falls—what do you do?", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "3cfb024c", "text": "d) List the end-to-end A/B-testing steps for this launch.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "282a9702", "text": "Hints", "type": "header-two", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}, {"key": "7ca0d933", "text": "Discuss engagement vs retention, heavy-tailed distributions, guardrail metrics, power calculation and success criteria.", "type": "unstyled", "depth": 0, "inlineStyleRanges": [], "entityRanges": [], "data": {}}], "entityMap": {}}