FLAME: Condensing Ensemble Diversity into a Single Network for Efficient Sequential Recommendation
sigir26-036 · Full research paper · Woojoo Kim, Junyoung Kim, Jaehyung Lim, Seongjin Choi, SeongKu Kang, Hwanjo Yu
Efficient and Long-Sequence Sequenti · 100%
Abstract
Sequential recommendation requires capturing diverse user behaviors, which a single network often fails to capture. While ensemble methods mitigate this, training multiple networks from scratch incurs high computational cost and instability from noisy mutual supervision. We propose Frozen and Learnable networks with Aligned Modular Ensemble (FLAME), a novel framework that condenses ensemble-level diversity into a single network for efficient sequential recommendation. During training, FLAME simulates exponential diversity using only two networks via modular ensemble, which dynamically combines sub-modules (e.g., layers) of each network to generate a rich space of diverse representation patterns. To stabilize training, FLAME pretrains and freezes one network as a semantic anchor and employs guided mutual learning to align diverse representations into the space of remaining learnable network. At inference, FLAME utilizes only the learnable network, achieving ensemble-level performance with zero overhead compared to a single network. Experiments on six datasets show that FLAME outperforms state-of-the-art baselines, achieving up to 7.69x faster convergence and 9.70% improvement in NDCG@20. Our code is available at https://github.com/woo-joo/FLAME_SIGIR26.
Assigned reviewers
| # | Reviewer | Match | Why (closest evidence publications in the taxonomy) | |
|---|---|---|---|---|
| 1 | Wei Guo 0006 | 53 | 80 Breaking the Bottleneck: User-Specific Optimization and Real-Time Inference Integration for Sequential Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation 73 FuXi-γ: Efficient Sequential Recommendation with Exponential-Power Temporal Encoder and Diagonal-Sparse Positional Mechanism (2026) Efficient Sequential Recommendation Architectures 63 Dataset Regeneration for Sequential Recommendation (2024) Recommendation Systems and Evaluation |
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| 2 | Jin Chen 0008 | 49 | 63 Enhancing Multi-Behavior Sequential Recommenders with Behavior-Aware Regularization (2025) Multi-Behavior Recommendation 54 RecStudio: Towards a Highly-Modularized Recommender System (2023) Recommendation Systems and Evaluation 53 Cooperative Retriever and Ranker in Deep Recommenders (2023) Recommendation with Search and Ranking |
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| 3 | Chunyang Wang 0001 | 48 | 63 MESA: Plugin Meta-Modulation for Transformer-Based Cold-Start Sequential Recommendation (2026) Sequential Recommendation with User Modeling and Profiling 57 Graph Diffusion-Based Representation Learning for Sequential Recommendation (2024) Sequential and Session-Based Graph Recommendation 55 Learning Graph-based Disentangled Representations for Next POI Recommendation (2022) Sequential and Session-Based Graph Recommendation |
Area chair
| Area chair | Match | |
|---|---|---|
| Yanan Niu | 55 |
Area-chair candidates (6)
| Yanan Niu assigned | 55 | 15 papers | |
| Xin Xin 0003 | 52 | 10 papers | |
| Kun Gai | 51 | 5 papers | |
| Maolin Wang 0001 | 51 | 15 papers | |
| Leyu Lin | 51 | 15 papers | |
| Pengyue Jia | 48 | 10 papers |
Candidates from the panel ranked by match score
| # | Reviewer | Match | Load | Why | |
|---|---|---|---|---|---|
| 1 | Bo Peng 0009 | 62 | 3 | 100 M2: Mixed Models With Preferences, Popularities and Transitions for Next-Basket Recommendation (2023) Efficient and Long-Sequence Sequential Recommendation 72 HAM: Hybrid Associations Models for Sequential Recommendation (Extended abstract) (2023) Sequential Recommendation with User Modeling and Profiling |
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| 2 | Fei Sun 0001 | 58 | 3 | 72 XDM: Improving Sequential Deep Matching with Unclicked User Behaviors for Recommender System (2022) Sequential Recommendation with User Modeling and Profiling 69 Contrastive Learning for Sequential Recommendation (2022) Contrastive and Self-Supervised Sequential Recommendation |
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| 3 | Jianling Wang | 58 | 3 | 100 A Hierarchical Self-Attentive Model for Recommending User-Generated Item Lists (2019) Efficient and Long-Sequence Sequential Recommendation 72 Recurrent Recommendation with Local Coherence (2019) Sequential Recommendation with User Modeling and Profiling |
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| 4 | Seongmin Park 0002 COI: co-author | 56 | 3 | 86 Temporal Linear Item-Item Model for Sequential Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation 72 Linear Item-Item Models with Neural Knowledge for Session-based Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation |
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| 6 | Wei Guo 0006 assigned | 53 | 3 | 80 Breaking the Bottleneck: User-Specific Optimization and Real-Time Inference Integration for Sequential Recommendation (2025) Efficient and Long-Sequence Sequential Recommendation 73 FuXi-γ: Efficient Sequential Recommendation with Exponential-Power Temporal Encoder and Diagonal-Sparse Positional Mechanism (2026) Efficient Sequential Recommendation Architectures |
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| 9 | Zhengyi Yang 0007 | 51 | 3 | 61 A Generic Learning Framework for Sequential Recommendation with Distribution Shifts (2023) Contrastive and Self-Supervised Sequential Recommendation 55 LLaRA: Large Language-Recommendation Assistant (2024) Sequential and Session-based Recommendation |
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| 11 | Lantao Hu | 51 | 3 | 70 Modeling User Fatigue for Sequential Recommendation (2024) Contrastive and Self-Supervised Sequential Recommendation 58 Sequential Recommendation for Optimizing Both Immediate Feedback and Long-term Retention (2024) Multi-Behavior and Multi-Interest Sequential Recommendation |
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| 12 | Shuchang Liu 0001 | 51 | 3 | 58 Sequential Recommendation for Optimizing Both Immediate Feedback and Long-term Retention (2024) Multi-Behavior and Multi-Interest Sequential Recommendation 56 Comprehensive List Generation for Multi-Generator Reranking (2025) Recommendation with Search and Ranking |
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| 13 | Bowen Zheng 0005 | 51 | 3 | 72 Reciprocal Sequential Recommendation (2023) Sequential Recommendation with User Modeling and Profiling 60 Enhancing Sequential Recommender with Large Language Models for Joint Video and Comment Recommendation (2025) Sequential and Session-based Recommendation |
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| 15 | Jieming Zhu | 50 | 3 | 80 FANS: Fast Non-Autoregressive Sequence Generation for Item List Continuation (2023) Efficient and Long-Sequence Sequential Recommendation 54 Can LLMs Outshine Conventional Recommenders? A Comparative Evaluation (2025) Efficiency and Deployment |
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| 16 | Yongjing Hao | 50 | 3 | 65 Feature-Level Deeper Self-Attention Network With Contrastive Learning for Sequential Recommendation (2023) Contrastive and Self-Supervised Sequential Recommendation 56 Learnable Model Augmentation Contrastive Learning for Sequential Recommendation (2024) Contrastive and Self-Supervised Sequential Recommendation |
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| 17 | Riwei Lai | 49 | 3 | 63 Proxy-Aware Cross-Domain Sequential Recommendation (2023) Cross-Domain Sequential Recommendation 61 Proxy-enhanced cross-domain sequential recommendation (2025) Cross-Domain and Cross-Market Sequential Recommendation |
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| 18 | Yang Song 0008 | 49 | 3 | 63 Understanding and Modeling Passive-Negative Feedback for Short-video Sequential Recommendation (2023) Multi-Behavior Recommendation 61 Learning and Optimization of Implicit Negative Feedback for Industrial Short-video Recommender System (2023) Multi-Behavior and Multi-Interest Sequential Recommendation |
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| 19 | Bo Chen 0023 | 49 | 3 | 63 ReLLa: Retrieval-enhanced Large Language Models for Lifelong Sequential Behavior Comprehension in Recommendation (2024) Sequential and Session-based Recommendation 61 Full-Stack Optimized Large Language Models for Lifelong Sequential Behavior Comprehension in Recommendation (2026) Sequential and Session-based Recommendation |
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| 20 | Qiang Luo 0004 | 49 | 3 | 72 FIM: Frequency-Aware Multi-View Interest Modeling for Local-Life Service Recommendation (2025) Sequential Recommendation with User Modeling and Profiling 59 MPFormer: Adaptive Framework for Industrial Multi-Task Personalized Sequential Retriever (2025) Multi-Task and Multi-Objective Optimization |
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| 21 | Jin Chen 0008 assigned | 49 | 3 | 63 Enhancing Multi-Behavior Sequential Recommenders with Behavior-Aware Regularization (2025) Multi-Behavior Recommendation 54 RecStudio: Towards a Highly-Modularized Recommender System (2023) Recommendation Systems and Evaluation |
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| 22 | Chen Wang 0052 | 49 | 3 | 69 Cluster-Aware Item Prompt Learning for Session-Based Recommendation (2025) LLM-Enhanced Sequential Recommendation 69 Confidence-Aware Fine-Tuning of Sequential Recommendation Systems Via Conformal Prediction (2025) Contrastive and Self-Supervised Sequential Recommendation |
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| 23 | Chongming Gao | 49 | 3 | 54 KuaiRec: A Fully-observed Dataset and Insights for Evaluating Recommender Systems (2022) Recommendation Systems and Evaluation 53 Large Language Models are Learnable Planners for Long-Term Recommendation (2024) Preference Alignment and Optimization |
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| 24 | James Caverlee | 49 | 3 | 66 Consistency-Aware Recommendation for User-Generated Item List Continuation (2020) Multimodal Recommendation for Domain Applications 63 Sequential Recommendation for Cold-start Users with Meta Transitional Learning (2021) Sequential Recommendation with User Modeling and Profiling |
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| 25 | Hao Liu 0078 | 49 | 3 | 61 Mitigating Distribution Shifts in Sequential Recommendation: An Invariance Perspective (2025) Contrastive and Self-Supervised Sequential Recommendation 56 WeaveRec: An LLM-Based Cross-Domain Sequential Recommendation Framework with Model Merging (2026) Efficiency and Deployment |
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| 26 | Xuanhua Yang | 48 | 3 | 72 Hierarchical User Long-term Behavior Modeling for Click-Through Rate Prediction (2025) CTR and Conversion Rate Prediction 53 Breaking the Relevance-Diversity Seesaw: Hierarchical LLM Reasoning with RL for Industrial Novelty Recommendation (2026) Preference Alignment and Optimization |
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| 27 | Chunyang Wang 0001 assigned | 48 | 3 | 63 MESA: Plugin Meta-Modulation for Transformer-Based Cold-Start Sequential Recommendation (2026) Sequential Recommendation with User Modeling and Profiling 57 Graph Diffusion-Based Representation Learning for Sequential Recommendation (2024) Sequential and Session-Based Graph Recommendation |
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| 28 | Hyunsik Yoo COI: co-author | 48 | 3 | 86 Capturing User Interests from Data Streams for Continual Sequential Recommendation (2026) Efficient and Long-Sequence Sequential Recommendation 83 Mixture of Sequence: Theme-Aware Mixture-of-Experts for Long-Sequence Recommendation (2026) Multi-Behavior and Multi-Interest Sequential Recommendation |
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| 29 | Jinxin Hu | 48 | 3 | 72 SASNet: Stage-aware Sequential Matching for Online Travel Recommendation (2022) Sequential Recommendation with User Modeling and Profiling 53 CSMF: Cascaded Selective Mask Fine-Tuning for Multi-Objective Embedding-Based Retrieval (2025) Recommendation with Search and Ranking |
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| 31 | Yongxin Ni | 48 | 3 | 62 Bridging NIP and MLM: A Unified Meta-Learning Framework for Sequential Recommendation (2026) Meta-Learning for Cold-Start Recommendation 55 Global and Personalized Graphs for Heterogeneous Sequential Recommendation by Learning Behavior Transitions and User Intentions (2022) Sequential and Session-Based Graph Recommendation |
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| 32 | Junwei Pan | 48 | 3 | 67 Multi-Sequence Attentive User Representation Learning for Side-information Integrated Sequential Recommendation (2024) Sequential Recommendation with Side and Multimodal Information 54 Empowering Large Language Model for Sequential Recommendation via Multimodal Embeddings and Semantic IDs (2025) Generative Recommendation and Item Tokenization |
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| 33 | Qijiong Liu | 47 | 3 | 80 FANS: Fast Non-Autoregressive Sequence Generation for Item List Continuation (2023) Efficient and Long-Sequence Sequential Recommendation 56 Lightweight Modality Adaptation to Sequential Recommendation via Correlation Supervision (2024) Sequential Recommendation with Side and Multimodal Information |
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| 34 | Jiangxia Cao | 47 | 3 | 61 Contrastive Cross-Domain Sequential Recommendation (2022) Cross-Domain and Cross-Market Sequential Recommendation 60 CDSRNP: Cross-Domain Sequential Recommendation via Neural Process (2025) Cross-Domain Sequential Recommendation |
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| 35 | Noveen Sachdeva | 47 | 3 | 72 Explicit Modelling of the Implicit Short Term User Preferences for Music Recommendation (2018) Sequential Recommendation with User Modeling and Profiling 55 Attentive neural architecture incorporating song features for music recommendation (2018) Sequential Recommendation with Side and Multimodal Information |
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| 36 | Hao Deng 0011 | 47 | 3 | 61 HeterRec: Heterogeneous Information Transformer for Scalable Sequential Recommendation (2025) Item Tokenization and Semantic IDs 52 REG4Rec: Reasoning-Enhanced Generative Model for Large-Scale Recommendation Systems (2026) Item Tokenization and Semantic IDs |