{"type":"excalidraw","version":2,"source":"https://AwesomeSystemDesign.dev","elements":[{"angle":0,"strokeColor":"#6577aa","backgroundColor":"#eef1fc","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-1"],"frameId":null,"roundness":null,"boundElements":[{"type":"text","id":"shape-1"}],"updated":0,"link":null,"locked":false,"id":"shape-0","type":"rectangle","seed":41,"x":36,"y":32,"width":390,"height":316.8,"customData":{"revealStep":1}},{"angle":0,"strokeColor":"#394557","backgroundColor":"transparent","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-1"],"frameId":null,"roundness":null,"boundElements":null,"updated":0,"link":null,"locked":false,"id":"shape-1","type":"text","seed":114,"x":56,"y":50,"width":350,"height":280.8,"fontSize":18,"fontFamily":1,"text":"Simple reverse-chronological feed of\npeople you\nfollow. No algorithmic ranking.\n\nImplementation:\n- Pure fanout-on-write (with hybrid\nfor celebs)\n- Redis sorted set by timestamp\n- No ML ranking needed\n- Filter: remove muted users, blocked\ncontent\n- Simple and fast","originalText":"Simple reverse-chronological feed of\npeople you\nfollow. No algorithmic ranking.\n\nImplementation:\n- Pure fanout-on-write (with hybrid\nfor celebs)\n- Redis sorted set by timestamp\n- No ML ranking needed\n- Filter: remove muted users, blocked\ncontent\n- Simple and fast","textAlign":"center","verticalAlign":"middle","containerId":"shape-0","lineHeight":1.3,"autoResize":false,"customData":{"revealStep":1}},{"angle":0,"strokeColor":"#628572","backgroundColor":"#edf5ee","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-2"],"frameId":null,"roundness":null,"boundElements":[{"type":"text","id":"shape-3"}],"updated":0,"link":null,"locked":false,"id":"shape-2","type":"rectangle","seed":187,"x":466,"y":32,"width":390,"height":878.4,"customData":{"revealStep":2}},{"angle":0,"strokeColor":"#394557","backgroundColor":"transparent","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-2"],"frameId":null,"roundness":null,"boundElements":null,"updated":0,"link":null,"locked":false,"id":"shape-3","type":"text","seed":260,"x":486,"y":50,"width":350,"height":842.4,"fontSize":18,"fontFamily":1,"text":"Personalized, ranked feed mixing:\n- In-network (people you follow):\n~50%\n- Out-of-network (recommended):\n~50%\n\nOut-of-network sources:\n- Posts liked/retweeted by people\nyou follow\n- Posts from similar users\n(embedding similarity)\n- Trending content in your interest\nclusters\n- Content from accounts you've\ninteracted with\nbut don't follow\n\nSimClusters (Twitter's approach):\n- Group users into ~150K interest\nclusters\n- Each user belongs to multiple\nclusters\n- Each tweet is scored against\nrelevant clusters\n- Recommend tweets that score high\nin user's\nclusters but weren't in their\nin-network feed\n\nCandidate sourcing:\n- In-network: 500 from feed cache\n- Out-of-network: 500 from\nSimClusters + social\nproof (friends liked this tweet)\n- Total: ~1000 candidates -> rank\n-> top 20","originalText":"Personalized, ranked feed mixing:\n- In-network (people you follow):\n~50%\n- Out-of-network (recommended):\n~50%\n\nOut-of-network sources:\n- Posts liked/retweeted by people\nyou follow\n- Posts from similar users\n(embedding similarity)\n- Trending content in your interest\nclusters\n- Content from accounts you've\ninteracted with\nbut don't follow\n\nSimClusters (Twitter's approach):\n- Group users into ~150K interest\nclusters\n- Each user belongs to multiple\nclusters\n- Each tweet is scored against\nrelevant clusters\n- Recommend tweets that score high\nin user's\nclusters but weren't in their\nin-network feed\n\nCandidate sourcing:\n- In-network: 500 from feed cache\n- Out-of-network: 500 from\nSimClusters + social\nproof (friends liked this tweet)\n- Total: ~1000 candidates -> rank\n-> top 20","textAlign":"center","verticalAlign":"middle","containerId":"shape-2","lineHeight":1.3,"autoResize":false,"customData":{"revealStep":2}},{"angle":0,"strokeColor":"#a68a53","backgroundColor":"#fff7e6","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-3"],"frameId":null,"roundness":null,"boundElements":[{"type":"text","id":"shape-5"}],"updated":0,"link":null,"locked":false,"id":"shape-4","type":"rectangle","seed":333,"x":36,"y":950.4,"width":420,"height":146.5,"customData":{"revealStep":3}},{"angle":0,"strokeColor":"#394557","backgroundColor":"transparent","fillStyle":"solid","strokeWidth":1.5,"strokeStyle":"solid","roughness":0.7,"opacity":100,"version":1,"versionNonce":1,"isDeleted":false,"groupIds":["step-3"],"frameId":null,"roundness":null,"boundElements":null,"updated":0,"link":null,"locked":false,"id":"shape-5","type":"text","seed":406,"x":56,"y":968.4,"width":380,"height":110.5,"fontSize":17,"fontFamily":1,"text":"Twitter's Two Timeline Modes\n\n\"Following\" tab (chronological):\n\n\"For You\" tab (algorithmic):","originalText":"Twitter's Two Timeline Modes\n\n\"Following\" tab (chronological):\n\n\"For You\" tab (algorithmic):","textAlign":"left","verticalAlign":"middle","containerId":"shape-4","lineHeight":1.3,"autoResize":false,"customData":{"revealStep":3}}],"appState":{"viewBackgroundColor":"#fbfbf8","gridSize":null},"files":{}}