https://www.chenk.top/en/tags/cold-start/Recent content in Cold Start on Chen Kai BlogHugoenFri, 09 Jan 2026 09:00:00 +0000https://www.chenk.top/en/recommendation-systems/14-cross-domain-cold-start/Fri, 09 Jan 2026 09:00:00 +0000https://www.chenk.top/en/recommendation-systems/14-cross-domain-cold-start/<blockquote> <p>When Netflix launches in a new country, it inherits millions of users with no history and a catalog with no local ratings. Amazon faces the same issue each time it opens a new product category. Pure collaborative filtering, the workhorse of warm-state recommendations, has nothing to compute. Techniques that make recommendations work in this scenario include: bootstrap heuristics for the first request, meta-learning after a few interactions, cross-domain transfer when a related domain is rich, and bandits to keep exploring once the model is confident. This post walks through these techniques, anchored to the papers they come from.</p>