🎬 How Netflix Knows What You’ll Watch Next

By Siri Lahari Chava

You know that moment when you finish a show and Netflix instantly lines up something new, and it’s exactly what you’re in the mood for? ​​It’s not luck, and it’s definitely not magic. Behind the scenes, data science is working overtime: tracking your habits, learning your tastes, and predicting what you’ll love next. It's proof that the smartest recommendations aren’t guesses, they’re data in disguise.

🔍 It’s All About Recommendations

Netflix’s entire business depends on one question: “What should we show you so you keep watching?”

To answer that, it uses a few clever strategies:

1. Collaborative Filtering

If you and someone else both loved Stranger Things, and they also liked Dark, Netflix figures you might enjoy Dark too. It’s like getting a recommendation from someone with eerily similar taste.

2. Content-Based Filtering

This method focuses on the shows themselves. If you’ve watched a bunch of sci-fi thrillers, Netflix will suggest more sci-fi, even if no one else is watching them. It’s about matching the ingredients of what you already like.

3. Hybrid Models

Netflix blends collaborative and content-based methods, adding context like:

đź“– When Netflix Got It Wrong (And Learned From It)

One night, I was winding down and looking for something light. I’d just finished Never Have I Ever and was hoping for another feel-good series. Netflix suggested You. If you’ve seen it, you know, it’s not light. It's psychological thriller meets stalker drama. I clicked anyway (curiosity won), but bailed halfway through the first episode. The next day, my recommendations shifted. Suddenly, I was seeing more rom-coms, less murder. That moment stuck with me. It reminded me that these systems aren’t static, they learn from what we click, what we skip, and even what we abandon. Every action is feedback. Every choice subtly rewrites the system’s understanding of us, shaping what we see next.

đź’» Try It Yourself: A Mini Recommender

Curious how this works under the hood? I built a simple demo using Python and Streamlit. Here’s how it works:

Open Mini Recommender

🚀 Why This Matters

Recommendation systems quietly shape how we discover things, make decisions, and spend our time. Building this demo showed me how even simple models can teach a lot about personalization and feedback.

âś… Final Takeaway

Next time Netflix nails your mood, remember there’s a whole world of math, modeling, and experimentation behind that single suggestion. Curious? Build your own recommender and see it in action!