Sumit

Sumit

@reachsumit.com

Senior MLE at Meta. Trying to keep up with the Information Retrieval domain! Blog: https://blog.reachsumit.com/ Newsletter: https://recsys.substack.com/

297 followers37 following3.9K posts

SearchHorizonBench: A Benchmark for Search Value in AI Agents Introduces a benchmark for judging when an extra web search is worth its cost for an AI agent, using paired runs that either answer directly or search further from the same point. ๐Ÿ“ arxiv.org/abs/2610.34714 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/EthanNing/Se...

github.comGitHub - EthanNing/SearchHorizonBench: A benchmark for search value in AI agents. Paired execution, gain prediction, and cost-aware decisions across 45,632 executions.A benchmark for search value in AI agents. Paired execution, gain prediction, and cost-aware decisions across 45,632 executions. - EthanNing/SearchHorizonBench

Can System-1-Style Decision Models Replace Dedicated Rerankers in RAG? A Systems Evaluation Tests decision models as reranker replacements. Truncation makes some competitive, but a tuned dedicated reranker is still faster and uses far less GPU memory. ๐Ÿ“ arxiv.org/abs/2610.34816

arxiv.orgCan System-1-Style Decision Models Replace Dedicated Rerankers in RAG? A Systems EvaluationRetrieval-augmented generation (RAG) systems often use a dedicated reranker to choose which retrieved candidates reach the language model. Reranking improves relevance but adds latency, so teams look ...

PinGER: Token-Efficient Generative Retrieval with Semantic IDs Pinterest presents its generative retriever that replaces nearest-neighbor search. An asymmetric attention mask trains with semantic ID supervision but serves only one token per item. ๐Ÿ“ arxiv.org/abs/2610.33435

arxiv.orgPinGER: Token-Efficient Generative Retrieval with Semantic IDsGenerative retrieval replaces nearest-neighbor search with token-by-token decoding of an item's semantic ID (SID). But existing SID-based methods primarily use L levels of tokens sequentially to repre...

LoopGR: Parameter-Efficient Scaling for Generative Recommendation via Recurrent Depth Reuses a shared decoder and a light context updater in recurrent loops to add depth without adding parameters, then distills it into a cheaper low-loop student. ๐Ÿ“ arxiv.org/abs/2610.34157

arxiv.orgLoopGR: Parameter-Efficient Scaling for Generative Recommendation via Recurrent DepthGenerative recommendation formulates item recommendation as autoregressive generation rather than a discriminative scoring problem. Although empirical studies exhibit favorable scaling behavior in rec...

Theoretically Sound Item Similarity Measures for Recommender Systems Derives item similarity measures from Bernoulli and multinomial Naive Bayes, and shows cosine similarity solves a specific optimization problem. ๐Ÿ“ arxiv.org/abs/2610.34402 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/noah-daniels...

arxiv.orgTheoretically Sound Item Similarity Measures for Recommender SystemsQuantifying the similarity between items is fundamental to neighborhood-based collaborative filtering, yet many commonly used similarity measures are heuristics that lack theoretical justification. Th...

Knowing When the Evidence Is Enough: Requirement-Directed Search with Horn-Closure Certificates Decides whether to answer, search again, or abstain using a per-query requirement hypergraph and Horn closure instead of having a model judge the evidence. ๐Ÿ“ arxiv.org/abs/2610.34684

arxiv.orgKnowing When the Evidence Is Enough: Requirement-Directed Search with Horn-Closure CertificatesAfter each Web search, a search-augmented model must decide whether its evidence suffices: answer, search again, or abstain. Prevailing systems leave this to holistic model judgement, which can accept...

SLIDE: Search-to-List Item Distillation for Single-Rollout Generative Retrieval Distills a teacher model's offline beam-search results into list-wise targets, so a smaller generative retrieval model can produce a full ranked list in one greedy pass. ๐Ÿ“ arxiv.org/abs/2610.34764

arxiv.orgSLIDE: Search-to-List Item Distillation for Single-Rollout Generative RetrievalGenerative retrieval (GR) typically relies on item-level beam search to retrieve candidates, leaving cross-item dependencies unmodeled and limiting direct optimization of list-level objectives. A natu...

Octen-WebGR: Scaling Generative Retrieval to 200 Million Web Pages Introduces a generative retriever that indexes 201 million web pages with two-token identifiers for navigational search. ๐Ÿ“ arxiv.org/abs/2610.35256 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/Octen-Team ๐Ÿค— huggingface.co/Octen

arxiv.orgOcten-WebGR: Scaling Generative Retrieval to 200 Million Web PagesNavigational search aims to find a single target page among hundreds of millions of web pages. Click tables work well for queries seen before but cannot generalise to new formulations, while embedding...

Unified Heterogeneous Feature Interaction via Effective-Rank Scaling for Recommender Systems Introduces a ranking model that combines behavior sequence modeling and feature interaction in a single backbone for multi-scenario recommendation. ๐Ÿ“ arxiv.org/abs/2610.35318

arxiv.orgUnified Heterogeneous Feature Interaction via Effective-Rank Scaling for Recommender SystemsLarge-scale industrial ranking models must jointly capture heterogeneous feature interactions, long-term user behaviors, and multi-scenario dependencies under stringent online serving constraints. Exi...

Towards a Unified Framework of Optimal Input-Side Dimensional Configuration for Deep CTR Prediction Introduces a framework that jointly selects samples, features, and embedding units for CTR prediction, using optimal transport to align the levels. ๐Ÿ“ arxiv.org/abs/2610.35695

arxiv.orgTowards a Unified Framework of Optimal Input-Side Dimensional Configuration for Deep CTR PredictionDeep click-through rate (CTR) prediction has achieved substantial success through increasingly expressive feature interaction architectures. However, predictive performance also depends on how input-s...

Do Similarity Measures Measure Similarity? How User Activity Creates Phantom Correlation in Recommender Systems Shows that differences in user activity alone make items look similar, even when users share no taste. ๐Ÿ“ arxiv.org/abs/2610.35765 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/Mfavier91/Ph...

arxiv.orgDo Similarity Measures Measure Similarity? How User Activity Creates Phantom Correlation in Recommender SystemsItem-item similarity is one of the oldest and most foundational signals in recommender systems: two items are assumed to be similar when the same users consume them. Despite the sparsity and scale of ...

ACARe: Agent-Context-Aware Reranker for Iterative Search Introduces a compact reranker for search agents that scores documents using the original question and reasoning trace, not just the agent's sub-query, improving retrieval and cutting searches. ๐Ÿ“ arxiv.org/abs/2610.35840

arxiv.orgACARE: Agent-Context-Aware Reranker for Iterative SearchIn agentic search, a document can match an agent-generated sub-query without helping answer the user's original question. Conventional rerankers score documents against the sub-query alone, overlookin...

Retriever-Free Retrieval: Navigating Documents with Decision Models Retrieves by walking down a corpus hierarchy, with a decision model scoring all candidates at each level in a single pass, without generating tokens. ๐Ÿ“ arxiv.org/abs/2610.35868

arxiv.orgRetriever-Free Retrieval: Navigating Documents with Decision ModelsWhile language models have become dramatically more capable, retrieval still largely relies on lexical matching or similarity in fixed embedding spaces. This creates a capability asymmetry: what the r...

Beyond Post-Hoc Rewards: Privileged Reasoning Exploration for Multimodal Embeddings Uses training-time positive and negative candidates to guide reasoning exploration for multimodal embeddings, with input-only inference. ๐Ÿ“ arxiv.org/abs/2610.32474

arxiv.orgBeyond Post-Hoc Rewards: Privileged Reasoning Exploration for Multimodal EmbeddingsAdvances in Multimodal Large Language Models (MLLMs) have driven substantial progress in multimodal embeddings. Recent methods exploit generative capabilities by augmenting embedded inputs with self-g...

TGR-EvoDAG: A DAG-based Multi-Agent Code Evolution Framework for Generative Recommendation on Tencent Tencent introduces a multi-agent framework that evolves generative recommendation code as a DAG of branches, with GPU cost planning for each pipeline stage. ๐Ÿ“ arxiv.org/abs/2610.32326

arxiv.orgTGR-EvoDAG: A DAG-based Multi-Agent Code Evolution Framework for Generative Recommendation on TencentLarge Language Model (LLM) agents have enabled automated code evolution for algorithm discovery. However, current recursive self-improvement (RSI) research for sequential recommendation faces a dilemm...

MICE to Meet You: From Re-ranking Only to End-to-End Retrieval Introduces MICE-P, which indexes MICE document representations with PLAID to build an end-to-end retrieval pipeline with cross-encoder-like effectiveness. ๐Ÿ“ arxiv.org/abs/2610.31932 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/xpmir/mice

arxiv.orgMICE to Meet You: From Re-ranking Only to End-to-End RetrievalLate-interaction models offer state-of-the-art efficiency-effectiveness trade-offs for neural retrieval by enabling document representations to be pre-computed and efficiently indexed. Yet, their rela...

From Item Scores to Semantic Tokens: Test-Time Collaborative Adaptation for Generative Recommendation Introduces a training-free way to use discriminative item scores to guide beam search in a frozen generative recommender before prefixes get pruned. ๐Ÿ“ arxiv.org/abs/2610.32098

arxiv.orgFrom Item Scores to Semantic Tokens: Test-Time Collaborative Adaptation for Generative RecommendationGenerative recommenders using semantic identifiers predict items through successive token decisions, but beam search may irreversibly prune promising item paths. This limitation is particularly conseq...

PersonalQuery-Benchmark: Evaluating Retrieval Robustness to Personalized User Expression Differences Introduces a benchmark where personalized query syntax and writing errors shift rankings for a fixed information need. ๐Ÿ“ arxiv.org/abs/2610.32164 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/cpxjazz123/P...

arxiv.orgPersonalQuery-Benchmark:Evaluating Retrieval Robustness to Personalized User Expression DifferencesExisting personalized information retrieval methods mainly model differences in user needs through user preferences and query intent, while paying little attention to the personalized expression diffe...

System One Models Are Not Better Rerankers Finds that decision (System One) fine-tuning never beats plain reranker fine-tuning on the same Qwen backbones, and its calibration advantage depends on the question wording. ๐Ÿ“ arxiv.org/abs/2610.32318 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/KanishkaGD/d...

arxiv.orgSystem One models Are Not Better RerankersSystem One models, or decision models, answer a question about an input with a calibrated probability instead of generated text. Within weeks of the first release, in September 2026, they were used as...

Agentic Memory Management Is the Next Frontier of Information Retrieval Presents a perspective paper arguing that managing an AI agent's memory is a natural extension of IR. Also shares a memory framework, a comparison with classic IR, and a research agenda. ๐Ÿ“ arxiv.org/abs/2610.32464

arxiv.orgAgentic Memory Management Is the Next Frontier of Information RetrievalInformation retrieval has long been focusing on connecting people with information they need to complete their tasks. Recently, the meaning of this has changed dramatically as more and more AI agents ...

Agentic Memory Management Is the Next Frontier of Information Retrieval Presents a perspective paper arguing that managing an AI agent's memory is a natural extension of IR. Also shares a memory framework, a comparison with classic IR, and a research agenda. ๐Ÿ“ arxiv.org/abs/2610.32464

arxiv.orgAgentic Memory Management Is the Next Frontier of Information RetrievalInformation retrieval has long been focusing on connecting people with information they need to complete their tasks. Recently, the meaning of this has changed dramatically as more and more AI agents ...

Knowledge Distillation across Item and Code Spaces for Parallel Generative Recommendation Proposes two objectives that distill a sequential recommender's item scores into a parallel semantic ID model, matching item distributions or code marginals. ๐Ÿ“ arxiv.org/abs/2610.32943

arxiv.orgKnowledge Distillation across Item and Code Spaces for Parallel Generative RecommendationGenerative recommendation with semantic IDs represents each item as a sequence of discrete codes derived from its semantic representation and predicts these codes to generate recommendations. Existing...

Separating Thinking from Spelling for Efficient Generative Recommendation Presents a GR system where the backbone reads the user history once into a compact concept and a light decoder runs the entire semantic ID beam search, which cuts serving cost. ๐Ÿ“ arxiv.org/abs/2610.32980

arxiv.orgSeparating Thinking from Spelling for Efficient Generative RecommendationGenerative recommenders retrieve items by writing their semantic IDs (SIDs) code by code under trie-constrained beam search, an approach now deployed on large web platforms. Standard autoregressive in...

Safe and Sufficient Caching: Per-Request Validated Evidence Reuse for Production Retrieval-Augmented Generation Amazon caches evidence chunks and checks access and source freshness before reuse, cutting latency and retrieval cost with zero invalid reuse. ๐Ÿ“ www.amazon.science/publications...

amazon.scienceSafe and sufficient caching: Per-request validated evidence reuse for production retrieval-augmented generationProduction Retrieval-Augmented Generation (RAG) systems serve repeated queries over evolving document corpora under user-specific access constraints. Standard pipelines perform full retrieval and gene...

TransX Technical Report: Scaling Sequence Transduction for Recommendation LinkedIn presents a recommender that separates history encoding, behavior memory, and candidate scoring so most work runs offline, letting models scale without raising serving cost. ๐Ÿ“ arxiv.org/abs/2610.20913

arxiv.orgTransX Technical Report: Scaling Sequence Transduction for RecommendationWe present TransX, a sequence-transduction framework and co-designed infrastructure for scaling industrial recommendation with explicit control over model-compute allocation and execution amortization...

Learning When to Think: Utility-Guided Adaptive Reasoning for Efficient Text Retrieval Trains a retrieval model to reason step by step and stop once extra reasoning stops helping, cutting generation cost and latency. ๐Ÿ“ arxiv.org/abs/2610.21030 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/yingtaoluo/A...

arxiv.orgLearning When to Think: Utility-Guided Adaptive Reasoning for Efficient Text RetrievalReasoning-conditioned embeddings can improve retrieval by progressively refining semantic constraints. However, additional reasoning may introduce over-generalized or semantically noisy abstractions t...

RecSoup: Efficient Model Merging Approach for Controllable Multi-Objective Recommendation Merges objective-specific recommenders after pruning conflicting parameters, so trade-offs can be tuned without retraining. ๐Ÿ“ arxiv.org/abs/2610.21220 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/35798642/REC...

arxiv.orgRecSoup: Efficient Model Merging Approach for Controllable Multi-Objective RecommendationRecommender systems often need to balance multiple conflicting objectives. Controllable Multi-Objective Recommendation (CMOR) enables dynamic adjustment of objective trade-offs at inference time witho...

Aligning LLMs with Sparse Retrieval via Adaptive Sparse Supervision Aligns an LLM with SPLADE's vocabulary space using input-adaptive truncation, keeping inverted-index retrieval with much lower storage and latency than prior LLM sparse retrievers. ๐Ÿ“ arxiv.org/abs/2610.21877

arxiv.orgAligning LLMs with Sparse Retrieval via Adaptive Sparse SupervisionWhile large language models (LLMs) offer strong semantic representations, their application to first-stage retrieval incurs substantial latency and storage costs. Neural sparse retrievers such as SPLA...

CASI: Credit Assignment via Set Intervention for Agentic Retrieval Xiaohongshu proposes assigning credit to jointly generated retrieval actions under one shared reward by scoring subsets of cached retrievals with Shapley values. ๐Ÿ“ arxiv.org/abs/2610.20293

arxiv.orgCASI: Credit Assignment via Set Intervention for Agentic RetrievalLarge language models increasingly generate multiple retrieval actions jointly, while downstream systems often provide only one reward for the resulting set. Broadcasting this reward provides a valid ...

ListQA: A Benchmark for Evaluating List-Formatted Factual Knowledge Retrieval in Large Language Models Introduces a benchmark where LLMs recall several facts from Wikipedia tables and return them as structured lists. ๐Ÿ“ arxiv.org/abs/2610.19165 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป listqa.github.io

arxiv.orgListQA: A Benchmark for Evaluating List-Formatted Factual Knowledge Retrieval in Large Language ModelsMany real-world questions demand not a single fact but an organized collection of them, yet existing factual knowledge benchmarks almost exclusively target single answer retrieval. We introduce ListQA...

RCER: Reconstructing Cross-Evidence Relations for Iterative Retrieval-Augmented Generation Introduces an iterative RAG method that reconstructs relations across retrieved passages to guide retrieval, select complementary passages, and compose answers. ๐Ÿ“ arxiv.org/abs/2610.19398

arxiv.orgRCER: Reconstructing Cross-Evidence Relations for Iterative Retrieval-Augmented GenerationIterative retrieval-augmented generation (RAG) accumulates knowledge from retrieved evidence to answer complex questions, but existing methods struggle to reconstruct entity correspondences and infere...

Retrieve What Helps, Only When It Helps: Agentic Reinforcement Learning for Selective Retrieval-Augmented Machine Translation Uses RL to teach an LLM when to retrieve for translation, and trains the retriever on translation quality, not similarity. ๐Ÿ“ arxiv.org/abs/2610.19528

arxiv.orgRetrieve What Helps, Only When It Helps: Agentic Reinforcement Learning for Selective Retrieval-Augmented Machine TranslationRetrieving external knowledge can improve large language model (LLM) translation by providing supplementary information such as idiom interpretations and terminology. However, existing retrieval-augme...

Cascaded Retrieval with Cross-Modal Query Refinement for Efficient Visual Document Search Introduces a cascaded framework that cuts latency in visual document retrieval by reranking a small candidate pool and refining the query with offline summaries. ๐Ÿ“ arxiv.org/abs/2610.20367

arxiv.orgCascaded Retrieval with Cross-Modal Query Refinement for Efficient Visual Document SearchRetrieving information from visually rich documents requires matching queries against pages that contain complex evidence in tables, figures, and layout-dependent structures. Current vision-language r...

Configuring RAG Systems: What Breaks, Where Originates, and How to Fix Presents an empirical study of configuration issues in open-source RAG systems, categorizing symptoms, root causes, and fix patterns across the pipeline stages. ๐Ÿ“ arxiv.org/abs/2610.18567 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป github.com/ideas-labo/r...

arxiv.orgConfiguring RAG Systems: What Breaks, Where Originates, and How to FixRetrieval-Augmented Generation (RAG) has emerged as a dominant paradigm for improving Large Language Model (LLM) by intertwining it with other components, such as a vector/graph database. Therefore, t...

Many Right Answers, One Training Example: Removing Responder Noise from GRPO for LLM Recommenders Introduces a system that rewards recommender lists against all responders' titles at once, making GRPO training cheaper. ๐Ÿ“ arxiv.org/abs/2610.17771 ๐Ÿ‘จ๐Ÿฝโ€๐Ÿ’ป lixin.ai/ReMaRk

arxiv.orgMany Right Answers, One Training Example: Removing Responder Noise from GRPO for LLM RecommendersA recommendation request on Reddit draws several replies, each naming different titles. When an LLM recommender is trained on such threads with reinforcement learning (RL), which replies should a gene...

Personalized LLM Recommendation with Semantic IDs: Autoregressive Beam Search vs. Multi-Token Prediction at Industry Scale Netflix compares beam search & multi-token prediction for generating Semantic IDs in LLM recommenders. Beam search wins on ranking. ๐Ÿ“ arxiv.org/abs/2610.15864

arxiv.orgPersonalized LLM Recommendation with Semantic IDs: Autoregressive Beam Search vs. Multi-Token PredictionLarge-scale personalization is shifting from embedding-table retrieval to LLM-based recommenders that generate the Semantic ID (SID) of the item to recommend, where each SID is a short sequence of dis...

UniSGR-V2: Stepwise Target-Side Feature Anticipation and Crossing for Generative Recommendation Introduces a system that predicts continuous target-item features at each semantic-ID decoding step and uses them for both code generation and ranking. ๐Ÿ“ arxiv.org/abs/2610.16132

arxiv.orgUniSGR-V2: Stepwise Target-Side Feature Anticipation and Crossing for Generative RecommendationSemantic-ID-based generative recommendation unifies retrieval and ranking through autoregressive decoding but differs structurally from discriminative models, which can directly access rich target-ite...

Label-Centric Knowledge Retrieval for Zero-Shot Text Classification Presents a system where a large LLM builds label definitions and boundary rules offline, and a small LLM classifies zero-shot by retrieving that knowledge instead of labeled examples. ๐Ÿ“ arxiv.org/abs/2610.16182

arxiv.orgLabel-Centric Knowledge Retrieval for Zero-Shot Text ClassificationFlagship large language models (LLMs) offer rich general knowledge and strong reasoning capabilities, but their high inference cost and latency limit their use for large-scale data labeling. We study ...

From a Large-Scale Teacher to Efficient Multimodal Students for Search Relevance Prediction eBay distills a GPT-4.1 relevance judge into smaller multimodal Gemma-3 models for e-commerce search, keeping near-teacher quality at much lower cost and latency. ๐Ÿ“ arxiv.org/abs/2610.16569

arxiv.orgFrom a Large-Scale Teacher to Efficient Multimodal Students for Search Relevance PredictionRelevance prediction between user queries and items is a fundamental component of e-commerce search systems. Traditionally, high-quality relevance labels are obtained through human judgment, which is ...

WeGR: Unified Generative Retrieval for Industrial Search Systems in WeChat Presents generative retrieval for WeChat search, with a tokenizer that adds collaborative signals without codebook collapse and an RL method that rewards semantic ID prefixes. ๐Ÿ“ arxiv.org/abs/2610.16979

arxiv.orgWeGR: Unified Generative Retrieval for Industrial Search Systems in WeChatGenerative retrieval (GR) offers a promising paradigm for industrial search by unifying candidate generation within an autoregressive framework. However, its effectiveness is limited by two key challe...

HASTE: Hierarchical and Attribute-aware Supervision for Generative Recommendation Replaces standard cross-entropy in generative recommendation with a level-aware loss over semantic IDs, and adds attribute prediction heads that help tail items. ๐Ÿ“ arxiv.org/abs/2610.17368

arxiv.orgHASTE: Hierarchical and Attribute-aware Supervision for Generative RecommendationGenerative recommendation models have shown promising results by representing items as semantic IDs and generating these IDs autoregressively. We introduce an approach showing that explicitly incorpor...