Ritangkar Dey
Home / Lab / Recommendation Engine
Search & Personalisation

Recommendation Engine

Hybrid recommender where every suggestion carries the reason it was made.

DeterministicFlagship WorkHybrid recsysExplainabilitySpring Boot
INTERACTIVE DEMOhard-coded · synthetic data · runs in your browser

The Problem

Cross-sell only works if shoppers see relevant items — and merchandisers will only trust a recommender that can explain itself.

How It Works

  1. Compute three normalised signals: popularity, content similarity (category, brand, use case, price bucket) and collaborative co-purchase.
  2. Blend them: 0.2 popularity + 0.4 content + 0.4 collaborative.
  3. Exclude owned items, rank, and generate an explanation naming the product that drove each result.

Technically Interesting

Classic recommender design with no black box: the top signal and the “driver” product are recorded, so explanations are a by-product of scoring, not an afterthought.

Why It Matters

Explainability is what lets recommendation logic move from experiment to something a business will put on a storefront.

Scope & honesty. Synthetic data (160 customers, 1,102 purchases, 124 products). Classical techniques — no embeddings or LLM.