Hey, I’m Harel.

I’m a Product Data Scientist. I’ve spent 12 years on consumer products used by hundreds of millions of people: Google Waze, Amazon Alexa Shopping and Viber.

There’s a wide gap between how product data science gets written about online and how it actually plays out on a Monday morning when a launch is contested and the numbers are not behaving. I started The Numerator to write into that gap.

Posts here are field notes from inside the work: the A/B test results that look clean and aren’t, the launch debates where everyone is using a different metric and the AI features that show up on your plate without a playbook.

The publication is named after the choice I think most of the work comes down to: every metric has a numerator, and defining what gets counted is where the real arguments happen.

If you finish a post and know one thing to try differently on Monday, the post worked.

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