Important Issues

Cold Start & Long-Tail Handling

  • Use pretrained content encoders

  • Use popularity prior & meta-learned embeddings

  • Rely on seller/group identity for long-tail bootstrapping

Data Labeling and Feedback Loops

  • Weakly supervised methods

  • Use LLMs to generate labels from noisy data

  • Online learning or continual training pipelines

System Design Aspects

  • Real-time embedding update pipelines

  • Feature freshness (e.g., contact count in last hour)

  • Ranking latency vs. relevance trade-offs

  • Efficient ANN index sharding