Beyond Dense Connectivity: Explicit Sparsity for Scalable Recommendation
Abstract
Recent progress in scaling large models has motivated recommender systems to increase model depth and capacity to better leverage massive behavioral data. However, recommendation inputs are high-dimensional and extremely sparse, and simply scaling dense backbones (e.g., deep MLPs) often yields diminishing returns or even performance degradation. Our analysis of industrial CTR models reveals a phenomenon of implicit connection sparsity: most learned connection weights tend towards zero, while only a small fraction remain prominent. This indicates a structural mismatch between dense connectivity and sparse recommendation data; by compelling the model to process vast low-utility connections instead of valid signals, the dense architecture itself becomes the primary bottleneck to effective pattern modeling. We propose SSR (Explicit Sparsity for Scalable Recommendation), a framework that incorporates sparsity explicitly into the architecture. SSR employs a multi-view ''filter-then-fuse'' mechanism, decomposing inputs into parallel views for dimension-level sparse filtering followed by dense fusion. Specifically, we realize the sparsity via two strategies: a Static Random Filter that achieves efficient structural sparsity via fixed dimension subsets, and Iterative Competitive Sparse (ICS), a differentiable dynamic mechanism that employs bio-inspired competition to adaptively retain high-response dimensions. Experiments on three public datasets and a billion-scale industrial dataset from AliExpress (a global e-commerce platform) show that SSR outperforms state-of-the-art baselines under similar budgets. Crucially, SSR exhibits superior scalability, delivering continuous performance gains where dense models saturate. The code is available at https://github.com/Atticus666/SSRNet.
Assigned reviewers
| # | Reviewer | Match | Why (closest evidence publications in the taxonomy) | |
|---|---|---|---|---|
| 1 | Xin Zhang 0091 | 56 | 75 Deep Dynamic Interest Learning With Session Local and Global Consistency for Click-Through Rate Predictions (2022) CTR and Conversion Rate Prediction 75 Deep Session Heterogeneity-Aware Network for Click Through Rate Prediction (2024) CTR and Conversion Rate Prediction 74 Graph-aware collaborative reasoning for click-through rate prediction (2023) CTR and Conversion Rate Prediction |
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| 2 | Wei Guo 0006 | 55 | 72 Breaking the Bottleneck: User-Specific Optimization and Real-Time Inference Integration for Sequential Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation 71 FuXi-γ: Efficient Sequential Recommendation with Exponential-Power Temporal Encoder and Diagonal-Sparse Positional Mechanism (2026) Efficient Sequential Recommendation Architectures 67 Enhancing Explicit and Implicit Feature Interactions via Information Sharing for Parallel Deep CTR Models (2021) CTR and Conversion Rate Prediction |
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| 3 | Jie Jiang 0015 | 52 | 84 Long-Sequence Recommendation Models Need Decoupled Embeddings (2025) CTR and Conversion Rate Prediction 67 Deep Pattern Network for Click-Through Rate Prediction (2024) CTR and Conversion Rate Prediction 67 AutoAttention: Automatic Field Pair Selection for Attention in User Behavior Modeling (2022) CTR and Conversion Rate Prediction |
Area chair
| Area chair | Match | |
|---|---|---|
| Kun Gai | 47 |
Area-chair candidates (7)
| Yanan Niu | 47 | 15 papers | |
| Kun Gai assigned | 47 | 5 papers | |
| Maolin Wang 0001 | 44 | 15 papers | |
| Xiaoyi Zeng COI: author | 44 | 11 papers | |
| Pengyue Jia | 42 | 10 papers | |
| Yankai Chen 0001 | 42 | 6 papers | |
| Xin Xin 0003 | 41 | 10 papers |
Candidates from the panel ranked by match score
| # | Reviewer | Match | Load | Why | |
|---|---|---|---|---|---|
| 1 | Ke Fei | 68 | 3 | 67 Entire-Space Variational Information Exploitation for Post-Click Conversion Rate Prediction (2025) CTR and Conversion Rate Prediction 67 Inverse Contrastive Representation Learning for Post-Click Conversion Rate Estimation (2026) CTR and Conversion Rate Prediction |
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| 2 | Junwei Pan | 59 | 3 | 72 Ads Recommendation in a Collapsed and Entangled World (2024) CTR and Conversion Rate Prediction 67 Long-Sequence Recommendation Models Need Decoupled Embeddings (2025) CTR and Conversion Rate Prediction |
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| 3 | Yu Zhang 0206 COI: co-author | 56 | 3 | 100 LREA: Low-Rank Efficient Attention on Modeling Long-Term User Behaviors for CTR Prediction (2025) CTR and Conversion Rate Prediction 100 Adversarial Filtering Modeling on Long-term User Behavior Sequences for Click-Through Rate Prediction (2022) CTR and Conversion Rate Prediction |
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| 4 | Xin Zhang 0091 assigned | 56 | 3 | 75 Deep Dynamic Interest Learning With Session Local and Global Consistency for Click-Through Rate Predictions (2022) CTR and Conversion Rate Prediction 75 Deep Session Heterogeneity-Aware Network for Click Through Rate Prediction (2024) CTR and Conversion Rate Prediction |
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| 5 | Wei Guo 0006 assigned | 55 | 3 | 72 Breaking the Bottleneck: User-Specific Optimization and Real-Time Inference Integration for Sequential Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation 71 FuXi-γ: Efficient Sequential Recommendation with Exponential-Power Temporal Encoder and Diagonal-Sparse Positional Mechanism (2026) Efficient Sequential Recommendation Architectures |
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| 6 | Jinxin Hu COI: co-author | 55 | 3 | 100 LREA: Low-Rank Efficient Attention on Modeling Long-Term User Behaviors for CTR Prediction (2025) CTR and Conversion Rate Prediction 72 Counterfactual Multi-task Learning for Delayed Conversion Modeling in E-commerce Sales Pre-Promotion (2026) CTR and Conversion Rate Prediction |
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| 7 | Yong He 0009 | 53 | 3 | 70 DCBT: A Simple But Effective Way for Unified Warm and Cold Recommendation (2023) CTR and Conversion Rate Prediction 68 GFlow-FT: Pick a Child Network via Gradient Flow for Efficient Fine-Tuning in Recommendation Systems (2022) CTR and Conversion Rate Prediction |
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| 8 | Jie Jiang 0015 assigned | 52 | 3 | 84 Long-Sequence Recommendation Models Need Decoupled Embeddings (2025) CTR and Conversion Rate Prediction 67 Deep Pattern Network for Click-Through Rate Prediction (2024) CTR and Conversion Rate Prediction |
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| 9 | Yi Zhang 0103 | 50 | 3 | 67 TF4CTR: Twin Focus Framework for CTR Prediction via Adaptive Sample Differentiation (2026) CTR and Conversion Rate Prediction 67 SimCEN: Simple Contrast-enhanced Network for CTR Prediction (2024) CTR and Conversion Rate Prediction |
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| 10 | Jieming Zhu | 48 | 3 | 72 FANS: Fast Non-Autoregressive Sequence Generation for Item List Continuation (2023) Efficient and Long-Sequence Sequential Recommendation 68 Data-free Knowledge Distillation for Reusing Recommendation Models (2023) CTR and Conversion Rate Prediction |
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| 11 | Bo Peng 0009 | 48 | 3 | 55 SWaT: Statistical Modeling of Video Watch Time through User Behavior Analysis (2025) User Behavior and Search Interaction 52 M2: Mixed Models With Preferences, Popularities and Transitions for Next-Basket Recommendation (2023) Efficient and Long-Sequence Sequential Recommendation |
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| 13 | Xuanhua Yang | 47 | 3 | 80 Hierarchical User Long-term Behavior Modeling for Click-Through Rate Prediction (2025) CTR and Conversion Rate Prediction 47 AdaSparse: Learning Adaptively Sparse Structures for Multi-Domain Click-Through Rate Prediction (2022) Advertising and Auction Mechanisms |
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| 15 | Qijiong Liu | 47 | 3 | 72 FANS: Fast Non-Autoregressive Sequence Generation for Item List Continuation (2023) Efficient and Long-Sequence Sequential Recommendation 71 Accelerating Generative Recommendation via Simple Categorical User Sequence Compression (2026) Generative Retrieval and Recommendation Architectures |
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| 16 | Yimeng Bai | 47 | 3 | 62 Unconstrained Monotonic Calibration of Predictions in Deep Ranking Systems (2025) CTR and Conversion Rate Prediction 46 LabelCraft: Empowering Short Video Recommendations with Automated Label Crafting (2024) Recommendation Systems and Evaluation |
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| 17 | Qiang Luo 0004 | 46 | 3 | 65 One Model to Serve All: Star Topology Adaptive Recommender for Multi-Domain CTR Prediction (2021) CTR and Conversion Rate Prediction 44 MPFormer: Adaptive Framework for Industrial Multi-Task Personalized Sequential Retriever (2025) Multi-Task and Multi-Objective Optimization |
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| 18 | Lichan Hong | 45 | 3 | 67 DCN V2: Improved Deep & Cross Network and Practical Lessons for Web-scale Learning to Rank Systems (2021) CTR and Conversion Rate Prediction 49 Off-policy Learning in Two-stage Recommender Systems (2020) Recommendation with Search and Ranking |
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| 20 | Jin Chen 0008 | 44 | 3 | 68 An Incremental Update Framework for Online Recommenders with Data-Driven Prior (2023) CTR and Conversion Rate Prediction 51 Automated Sparse and Low-Rank Shallow Autoencoders for Recommendation (2025) Efficient and Lightweight Graph Collaborative Filtering |
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| 21 | Gyuseok Lee | 44 | 3 | 71 Capturing User Interests from Data Streams for Continual Sequential Recommendation (2026) Efficient Sequential Recommendation Architectures 39 Continual Collaborative Distillation for Recommender System (2024) Efficient and Lightweight Graph Collaborative Filtering |
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| 23 | Yuta Saito | 44 | 3 | 66 Doubly Robust Estimator for Ranking Metrics with Post-Click Conversions (2020) CTR and Conversion Rate Prediction 49 Off-Policy Evaluation of Ranking Policies under Diverse User Behavior (2023) Recommendation with Search and Ranking |
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| 24 | Yongjing Hao | 44 | 3 | 67 Exploiting Intra and Inter-field Feature Interaction with Self-Attentive Network for CTR Prediction (2021) CTR and Conversion Rate Prediction 44 Feature-Level Deeper Self-Attention Network With Contrastive Learning for Sequential Recommendation (2023) Contrastive and Self-Supervised Sequential Recommendation |
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| 25 | Jiangxia Cao | 44 | 3 | 67 ChorusCVR: Chorus Supervision for Entire Space Post-Click Conversion Rate Modeling (2026) CTR and Conversion Rate Prediction 44 CDSRNP: Cross-Domain Sequential Recommendation via Neural Process (2025) Cross-Domain Sequential Recommendation |
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| 26 | Fei Sun 0001 | 43 | 3 | 47 Personalized re-ranking for recommendation (2019) Recommendation with Search and Ranking 46 Neural Re-ranking in Multi-stage Recommender Systems: A Review (2022) Recommendation Systems and Evaluation |
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| 27 | Shuchang Liu 0001 | 42 | 3 | 48 M3oE: Multi-Domain Multi-Task Mixture-of Experts Recommendation Framework (2024) Multi-Scenario and Multi-Domain CTR Prediction 47 Comprehensive List Generation for Multi-Generator Reranking (2025) Recommendation with Search and Ranking |
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| 28 | Min Hou 0004 | 42 | 3 | 68 Clustering based Behavior Sampling with Long Sequential Data for CTR Prediction (2022) CTR and Conversion Rate Prediction 45 Pre-training General User Representation with Multi-type APP Behaviors (2024) Recommendation Systems and Evaluation |
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| 29 | Bo Chen 0023 | 42 | 3 | 46 A Comprehensive Survey on Automated Machine Learning for Recommendations (2024) Recommendation Systems and Evaluation 45 ReLLa: Retrieval-enhanced Large Language Models for Lifelong Sequential Behavior Comprehension in Recommendation (2024) Sequential and Session-based Recommendation |
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| 30 | Huifeng Guo | 42 | 3 | 71 FuXi-γ: Efficient Sequential Recommendation with Exponential-Power Temporal Encoder and Diagonal-Sparse Positional Mechanism (2026) Efficient Sequential Recommendation Architectures 51 Scenario-Wise Rec: A Multi-Scenario Recommendation Benchmark (2025) Recommendation Systems and Evaluation |
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| 33 | Jianling Wang | 42 | 3 | 52 A Hierarchical Self-Attentive Model for Recommending User-Generated Item Lists (2019) Efficient and Long-Sequence Sequential Recommendation 45 Sequential Recommendation for Cold-start Users with Meta Transitional Learning (2021) Sequential Recommendation with User Modeling and Profiling |
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| 34 | Lantao Hu | 41 | 3 | 47 Unsupervised Ranking Ensemble Model for Recommendation (2024) Recommendation with Search and Ranking 47 Comprehensive List Generation for Multi-Generator Reranking (2025) Recommendation with Search and Ranking |
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| 35 | Noveen Sachdeva | 41 | 3 | 44 Explicit Modelling of the Implicit Short Term User Preferences for Music Recommendation (2018) Sequential Recommendation with User Modeling and Profiling 44 How Useful are Reviews for Recommendation? A Critical Review and Potential Improvements (2020) Recommendation Systems and Evaluation |
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| 36 | Xiao Zhang 0034 | 41 | 3 | 47 UniSAR: Modeling User Transition Behaviors between Search and Recommendation (2024) Recommendation with Search and Ranking 46 Benefit from Rich: Tackling Search Interaction Sparsity in Search Enhanced Recommendation (2025) Recommendation with Search and Ranking |