  Click-Through Rate (CTR) prediction is one of the most important machine
learning tasks in recommender systems, driving personalized experience for
billions of consumers. Neural architecture search (NAS), as an emerging field,
has demonstrated its capabilities in discovering powerful neural network
architectures, which motivates us to explore its potential for CTR predictions.
Due to 1) diverse unstructured feature interactions, 2) heterogeneous feature
space, and 3) high data volume and intrinsic data randomness, it is challenging
to construct, search, and compare different architectures effectively for
recommendation models. To address these challenges, we propose an automated
interaction architecture discovering framework for CTR prediction named
AutoCTR. Via modularizing simple yet representative interactions as virtual
building blocks and wiring them into a space of direct acyclic graphs, AutoCTR
performs evolutionary architecture exploration with learning-to-rank guidance
at the architecture level and achieves acceleration using low-fidelity model.
Empirical analysis demonstrates the effectiveness of AutoCTR on different
datasets comparing to human-crafted architectures. The discovered architecture
also enjoys generalizability and transferability among different datasets.
