awesome-search

Awesome Search

I've been building e-commerce search applications for 15+ years. Below is a list of some publications, conferences, and books that have inspired me, grouped by topic. If an item fits into multiple topics, it appears in multiple sections.

:star: Star us on GitHub — it helps!

Latest Changes

• 2026.44
• 2026.43
• 2026.42
• 2026.41
• 2026.40

---

Global Table of Contents

A map of every note in the vault organized by category and theme. This index tracks concepts, topics, people, tools, companies, case studies, conferences, and datasets.

Maps of Content

• All about Information Retrieval & Search — top-level overview
• Concepts · Topics · People · Tools · Case Studies · Videos · Conferences · History · Index

---

Concepts

Lexical & Sparse Retrieval

BM25 · Bayesian BM25 · Bayesian Optimization · Bag-of-Documents Model · Full-Text Search · WAND · Block-Max WAND · Sparse Vector Retrieval · Learned Sparse Retrieval · SPLADE · ELSER · miniCOIL · Sparse Embeddings · Collocations · Out-of-Vocabulary

Dense Retrieval & Embeddings

Embeddings · Dense Embeddings · Dense Vector Retrieval · Semantic Search · Asymmetric Semantic Search · Bi-Encoder · Dense Passage Retriever · BERT · Word2Vec · Word2Box · Concept Vectors · Matryoshka Embeddings · Multimodal Embeddings · Compositional Embeddings · Task-Aware Embeddings · Embedding Fine-tuning · Pooling · Zero-Shot Retrieval · Vector Similarity Metrics · Contrastive Gap · Modality Gap

Geometric & Set-Theoretic Embeddings

Set-Theoretic Embeddings · Box Embedding · Gaussian Embedding · Poincaré Embedding · Region-Based Representation

ANN Indexing & Quantization

ANN · Brute-Force Vector Search · Maximum Inner Product Search · HNSW · IVF · LSH · ACORN-1 · Vector Filtering · Vector Index Updates · Wormhole Vectors · Vector Quantization · Scalar Quantization · Binary Quantization · BBQ · RaBitQ · TurboQuant · ASH · ITQ · Token Pooling

Dimensionality Reduction

Dimensionality Reduction · PCA · UMAP · t-SNE

Late Interaction & Multi-Vector

Late Interaction · ColBERT · ColPali · MUVERA · PLAID

Reranking & Cross-Encoders

Reranking · Asymmetric Re-ranking · Bag of Decisions · BlitzRank · Calibrated Relevance Probability · Cross-Encoder · Fast but Not Late Interaction · MonoT5 · RankGPT · RankLLaMA · Knowledge Distillation · Relational Transformer

Learning to Rank

Learning to Rank · LambdaMART · LambdaLoss · RankNet · LTR Feature Engineering · Hashing Trick · Ranking Objectives · Ranking Signal Selection · Pointwise Relevance Evaluation · Pairwise Relevance Evaluation · Listwise Relevance Evaluation · Feature Store · Results Boosting

Hybrid Search & Score Fusion

Hybrid Search · Reciprocal Rank Fusion · Distribution-Based Score Fusion · Linear Score Combination · Relative Score Fusion · Score Normalization · Semantic Boosting

Query Understanding

Query Understanding · Query Segmentation · Query Specificity · Query Types · Query Sampling · Search Intent · Intent Drift · Keywords Extraction · Compositional Queries

Lexical Query Operations

Tokenization · Spelling Correction · Synonyms · Stopwords · Autocomplete · Query Expansion · Query Relaxation · Query Rewriting

Evaluation & Metrics

Search Evaluation · NDCG · NDCG-m · NDCG-f · MAP · MRR · ERR · Brier Score · Expected Calibration Error · Precision and Recall · Hit Rate at K · UDCG · Diversity Metrics · Judgment Lists · ESCI Label Scheme · Implicit Judgments · Kendall Rank Correlation · Rank-Biased Overlap · Inter-Annotator Agreement · LLM as Judge · Levels of Judge Agreement · Judge Calibration · Prompt Optimization · Prompt Sensitivity · Adversarial Relevance Judgment · Staged Judging · Semantic Relevance · Outcome-Based Relevance · Statistical Significance in Search Evaluation · Interleaving · Isolated Feedback Loops · Out-of-Time Validation · Benchmark Contamination · Session-Based Evaluation · Vector Search Evaluation · Hallucination Detection · Needle in a Haystack Test · Relevance feedback · APD

Behavioral Signals & Bias

Click Models · Neural Click Models · Click Signals · Clicks Residual · Impression Bias · Position Bias · Presentation Bias · Ranking Signal Selection · Signal Downboosting · Personalization · Exploration vs Exploitation

Agentic, Generative & RAG

Agentic Search · Agentic Memory · Model Context Protocol · Agentic Query Workload · Conversational Search · RAG · Generative Retrieval · Differentiable Search Index · Direct Corpus Interaction · Purpose-Built Agentic Search Models · System One Model · SIRA · Search-R1 · Reinforcement Learning for Search · Semantic IDs · TIGER · RQ-VAE · Context Engineering · DICE · Clean Context · Hypothetical Document Embeddings · Steering Vectors · GraphRAG · HippoRAG · Long-Context RAG · Prompt Compression · Query Routing · LLM Guardrails · Adaptive Retrieval

Model Fine-Tuning & Serving

LoRA · QLoRA · PEFT · GGUF · Hard Negative Mining · Catastrophic Forgetting · Contrastive Learning · Knowledge Distillation · Reinforcement Learning for Calibrated Decisions · Synthetic Query Generation · Consistency Filtering · PROMPTAGATOR · FLAN-T5 · Domain-Specific Semantic Gaps · Dataset Types for Embedding Fine-Tuning · Embedding Loss Functions · Hyperparameter Tuning for Embedding Fine-Tuning

Search Architecture & Operations

Search Architecture · Retrieval Pipeline · Sharding · Compute-Storage Disaggregation · Unified Search Index · Denormalization for Search · Search Governance · Search Team · Search Results Explainability · Text Chunking · Knowledge Graph Search

Search UX & Discovery

Faceted Search · Federated Search · Search Scopes · Zero Results · Results Merchandising · MMR · Vertical Selection

---

Topics

Retrieval & Ranking Techniques

Reasoning Reranking · RL-Trained Search Agents · Late Interaction in Elasticsearch · Late Interaction in OpenSearch · Late Interaction in Qdrant · Late Interaction in Vespa · Elasticsearch Learning to Rank · Vespa Learning to Rank · Tuning BM25 for E-commerce Search · Vector Search Tradeoffs · Dimensionality Reduction vs Quantization · PCA vs t-SNE for Retrieval · Search UX · Search UX Research · Search Result Diversity · Multilingual Search · Personalization in Search · Agentic Memory for Search Personalization · Query Classification · Query Understanding in Practice · Spelling Correction in Search · Synonyms and Vocabulary Management · Autocomplete and Autosuggest · Conversational and Agentic Search · Interaction Paradigms

Domains & Platforms

E-commerce Search · Two-Sided Marketplace Ranking · Enterprise Search · Search using PostgreSQL · Search Platforms · Extreme Search Systems · Migration between Search Engines · Elasticsearch vs OpenSearch · Federated vs Unified Search · Multi-Tenancy in Search

Quality & Operations

A-B Testing for Search · Duality in Measuring Search · NDCG Variants · Search Quality Assurance · Relevance Program Setup · Relevance Evaluation Tools Compared · Quepid Beyond Supported Engines · Model Selection and Fine-Tuning Evaluation · Retrieval Benchmarks and Leaderboards · E-commerce Search Evaluation Datasets · Outcome-Based vs Semantic Relevance · Embedding Models Compared · Search Observability

Team, Career & Community

Hiring for Search · How to Start a Career in Search · Managing a Search Team · Understaffed Search Team · Search Consultancy · Search Communities · Women of Search · Events and Conferences

Learning Resources

Books · Courses

Strategy & Meta

Frontier of Search · Frontier of Search 2025 · Frontier of Search 2026 · Frontier of Search 2026 Part 2 · Economics of Search · Search Problem Archetypes · Fun and Philosophy · Reception of Jev

---

Tools

Search & Vector Engines

Elasticsearch · OpenSearch · Solr · Manticore Search · FAISS · autofaiss · Milvus Vector DB · Pinecone Vector DB · Qdrant Vector DB · qdrant-es-gateway · Weaviate Vector DB · turbopuffer Search DB · PostgreSQL · ParadeDB · VectorChord · opensearch-muvera-plugin

PostgreSQL Extensions

pgvector · pgvectorscale · pg_textsearch · pg_trgm · psql_bm25s

SQLite Extensions

sqlite-sparse

Ranking & ML Libraries

LightGBM · XGBoost · CatBoost · RankLib · Metarank · eland

Embedding Training

Sentence Transformers · qdrant-sparse-finetune · qdrant-relevance-feedback

RAG & LLM Frameworks

LlamaIndex · LangChain · Haystack (deepset) · DSPy · GEPA · AutoRAG · RAGAS

Relevance & Query Tooling

Querqy · Quepid · Embabel · Embabel DICE · django-dice · Search Relevance Workbench · OpenSearch Relevance Agent · Elasticsearch Relevance Studio · Rated Ranking Evaluator · Releval · Langfuse · Jevals · User Behavior Insights · ann-benchmarks · SID-1 · hev-rerank

ML & Model Serving

LightGBM · XGBoost · CatBoost · RankLib · ONNX · eland · Jev · Voyage rerank-3 · Lychee-Reranker · CLEPR · FastEmbed

---

Companies

Ailog · Airbnb · Algolia · Allegro · Amazon Web Services · Baymard Institute · Bonsai · Booking.com · Canva · Carousell · Cohere · Contextual AI · Criteo · Delivery Hero · Dropbox · eBay · Elastic · Elsevier · Empathy · Enterprise Knowledge LLC · Etsy · Google · Grubhub · Hornet · Jina AI · Kleinanzeigen · LightOn AI · LinkedIn · Meta · Mixedbread · MongoDB · Netflix · Nielsen Norman Group · OpenSource Connections · Otto · Pinecone · Qdrant · Reddit · RelativeDB · SID.ai · Sease · Shaped · Shopify · Skyscanner · Slack · Spotify · The Search Juggler · Tiger Data · Twitter · TypeSafe · Uber · Valyu AI · Vespa · Vinted · Voyage AI · Weaviate · Zalando · searchHub · turbopuffer

---

Case Studies

Airbnb - ML-Powered Experiences Ranking · Bonsai - Designing Search for a Relational Database · Canva - Search Pipeline Modernization · Etsy - Search Quality and Query Understanding · foodpanda - Classifying 300K Noisy Search Terms Across 16 Markets · Hybrid Fusion Failure - BM25 Displacing Reference Documents · Kleinanzeigen - Vespa Migration for Homepage Feed · Netflix - Content Search Architecture · Reddit - Vector Database Selection · Skyscanner - Learning to Rank for Flights · Slack - Enterprise Message Search with LTR · Uber Eats - Scaling Search for Food Delivery · Vespa - Ranking Without Labels on CORD-19 · Vinted - Migrating Search from Elasticsearch to Vespa · Zalando - Self-DoS via Facet Aggregation

---

Videos

Conference talks and recorded presentations.

Max Irwin - The Search Engine Migration Circus — Max Irwin, OpenSource Connections; Haystack Live talk on search-engine migration (playbook, "Hello Search", feature parity, the "damage" metric, war stories)

Haystack US 2022 - Bayesian Optimization of Relevance at Shopify — Doug Turnbull & Andy Toulis, Shopify; Haystack US 2022 talk on Bayesian Optimization for retuning BM25 k1/b, with a worked case study on product-title length normalization and a presentation-bias loophole caught mid-experiment

Choosing Indexes for Similarity Search (Faiss in Python) — James Briggs, Pinecone; hands-on FAISS tutorial comparing Flat, LSH, HNSW, and IVF on Sift1M

Rene Kriegler - Query Relaxation — Rene Kriegler, OpenSource Connections; Query Relaxation as a query recommendation problem — word-shape heuristics, term frequency, Word2Vec and a neural network compared for predicting which term to drop

Roman Grebennikov - Personalizing Search Results in Real-Time — Roman Grebennikov, Findify; MICES 2019 talk on real-time LTR personalization — Position Bias feedback loops, shuffled Exploration vs Exploitation segments, cross-merchant generic models, purchase-weighted perfect rankings

Evgeniya Sukhodolskaya - Fine-Tuning Sparse Neural Retrievers for E-Commerce — Evgeniya Sukhodolskaya, Qdrant; MICES 2026 talk on making SPLADE fine-tuning approachable — why MS MARCO-trained sparse models misfire on catalogs, the ANCE Hard Negative Mining loop, full vs inference-free SPLADE, specialize vs generalize

Evgeniya Sukhodolskaya - Relevance Feedback Inside the Search Engine — Evgeniya Sukhodolskaya, Qdrant; Berlin Buzzwords 2026 talk on index-native Relevance Feedback — model-generated feedback steering HNSW hop selection instead of reranking a top-k, Knowledge Distillation of a reranker into the index, and the case against black-box search engines

Hajer Bouafif - Personalize Search Results with OpenSearch Agentic Memory — Hajer Bouafif, Amazon Web Services; Berlin Buzzwords 2026 talk on Agentic Memory as the substrate for search Personalization — preferences inferred offline by an LLM from UBI clickstream, applied online via Query Rewriting and Reranking, with reasoning kept off the query path

Andrei Cristea - Qdrant Vector Search and Hybrid Routing — Andrei Cristea, Qdrant; Haystack EU lightning talk on hybrid routing — a small classifier sends each query to sparse, dense or RRF and beats always-on fusion, where an LLM router kept defaulting to RRF

Podcasts

Vector Podcast — Dima Kan, Aiven; interview series running since October 2021 (38 episodes) covering vector search, search engines and the businesses around them — vector database founders interviewed mid-build, HNSW co-author Yury Malkov, and on-site batches from Berlin Buzzwords

---

Conferences

See the Conferences MOC. Berlin Buzzwords · Haystack EU · Haystack US · MICES

---

Datasets

ADE Corpus V2 · Amazon ESCI Dataset · ANTIQUE · BEIR · BRIGHT · CLERC · DSGlobal · ESCI-S Dataset · Home Depot Product Search Relevance · LLMJudge · LocalNews · LongEmbed · LoTTE · MAIR · MIRACL · MS MARCO · MTEB · Natural Questions · NewsSpectrum · QASPER · RelBench · RTEB · SIFT1M · STaRK · TREC Deep Learning Track · TREC-COVID · WANDS Dataset

---

People

A — Achinoam Soroker · Adrien Grand · Aleksas Kateiva · Alexander Marquardt · Amélie Chatelain · Andre Charton · Andrea Schütt · Andreas Wagner · Andrei Cristea · Andrew Kornilov · Andrew McCallum · Andrew Mende · André Mourão · Andy Toulis · Annabell Schäfer · Anthony K.H. Tung · Antoine Chaffin · Aparna Dhinakaran · Asif Makhani · Atita Arora · Audrey Lorberfeld

B — Benjamin Trent · Billy Chan · Bobby Mohammed · Brage Vik

C — Chadha Sridi · Charles L. A. Clarke · Charlie Hull · Chris Fournie · Congzhe Su

D — Dai Sugimori · Dainius Jocas · Daniel Doro · Daniel Henneberger · Daniel Tunkelang · David Albrecht · David Argüello Sánchez · Davit Khachaturyan · Dima Kan · Diogo Almeida · Dmitriy Meyerzon · Dotan Horovits · Doug Turnbull · Douwe Kiela · Dustin Coates · Dylan Castillo · Dylan Couzon

E — Erik Hatcher · Ernestas Poškus · Eugene Yan · Elzbieta Jakubowska · Evgeniya Sukhodolskaya

F — Fernando Diaz · Florent Krzakala · Florian Narr · Fraidoon Omarzai · Francesco Casalegno · Frank Goortani · Freddy Domínguez

G — Geoffrey Hinton · Giovanni Fernandez-Kincade · Gustavo Llermaly

H — Hailey Cheong · Hajer Bouafif · Han Xiao · Han-chung Lee · Hassam Chundrigar · Heather Hedden · Hev · Honza Král · Hugo Galvão

I — Isabella Tromba · Iulia Brezeanu · Ivan Pleshkov

J — Jagadeesh Chandra · Jaideep Ray · Jaime Arguello · James Briggs · James Rubinstein · Jamie Callan · Janani Narayanan · Janu Verma · Jason Lee · Jeffrey Rengifo · Jettro Coenradie · Jithendrasaikilaru · Jo Kristian Bergum · Jodi Sloan · Joanna Marhula · Jonas Schulz · Jonathan Larson · Joon-Pil (JP) Hwang · Jose Parreño

K — Karthik Ramasamy · Kemal Erdem · Keyur Ramoliya

L — Lakhan Bukkawar · Lakshmi Devi Prakash · Laura Dietz · Laura Ham · Laurynas Jasiukėnas · Laurens van der Maaten · Laxman Dhulipala · Leo Schuster · Leonie Monigatti · Lester Solbakken · [Li Zhang](https://frutik.github.io/awesome-search/Peop