All drills

Build a Recommender from Scratch

What you'll be able to do

Build the system behind every "recommended for you" row you have ever seen — and, more importantly, the evaluation harness that tells you honestly whether it works, which is the part most tutorials skip and most production teams get wrong.

Amazon's item-to-item recommendations, the Netflix Prize solutions, and Spotify's early collaborative filtering all run on the techniques you build here; every modern recommender is measured against exactly these baselines.
Start this internship
Create an account to unlock the 13 sections, the workbench, and AskThili.
Begin

Sections

1. Build a Recommender from Scratch
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2. The Recommendation Problem
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3. MovieLens, Represented Honestly
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4. Similarity on Implicit Data
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5. Similarity on Explicit Data
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6. Splitting by Time
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7. Baselines First
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8. User-Based Collaborative Filtering
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9. Item-Based Collaborative Filtering
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10. How Recommendations Are Actually Judged
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11. Matrix Factorization
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12. Bias, Done Right
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13. What Breaks Next
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Dig deeper

📄Item-Based Collaborative Filtering Recommendation Algorithms (Sarwar, Karypis, Konstan & Riedl, 2001, WWW)
paper
📄Matrix Factorization Techniques for Recommender Systems (Koren, Bell & Volinsky, 2009, IEEE Computer)
paper
📄Amazon.com Recommendations: Item-to-Item Collaborative Filtering (Linden, Smith & York, 2003, IEEE Internet Computing)
paper
📄Collaborative Filtering for Implicit Feedback Datasets (Hu, Koren & Volinsky, 2008, ICDM)
paper
📄The MovieLens Datasets: History and Context (Harper & Konstan, 2015, ACM TiiS)
paper
🔗thili-ai/thilirec — reference implementation
code