Empowering Carrot Ads with Domain Adaptive Learning
5/4/2026
This post introduces and details Instacart's Domain Adaptive Learning approach for its Carrot Ads platform. It explains the 'cold start' problem for new partners and how domain adaptation addresses it by transferring knowledge from the Instacart Marketplace to partner domains. The technical implementation involves adapting a wide and deep pCTR model architecture at both the neural network level (shared embedding layers, fine-tuning specific layers) and the training data level (matching features, feature trimming). The post highlights the benefits of this approach, including improved performance in low-data and high-data scenarios, efficiency, and generalization. It also discusses learnings, such as the need for human-in-the-loop verification for negative transfer, and outlines future work on an automated Domain Adaptation Platform.