Building a scoring engine with pure TypeScript functions (no ML, no backend)

We needed to score e-commerce products across multiple dimensions: quality, profitability, market conditions, and risk. The constraints: Scores must update in real time Must run entirely in the browser (Chrome extension) Must be explainable (not a black box) We almost built an ML pipeline — training data, model serving, APIs, everything. Then we asked a simple question: Do we actually need machine learning for this? The answer was no. We ended up building several scoring engines in pure