A Comprehensive Review of Recommender Systems: Transitioning from Theory to Practice
Shaina Raza, Mizanur Rahman, Safiullah Kamawal, Armin Toroghi, Ananya Raval, Farshad Navah, Amirmohammad Kazemeini
TL;DR
This survey assesses the progression of Recommender Systems from foundational theory to practical deployment between 2017 and 2024. It organizes methods into foundational, deep-learning, graph-based, sequential, knowledge-based, RL, LLM-based, and multimodal families, and covers specialized domains such as context-aware, review-based, aspect-based, and fairness-driven RS. The paper highlights challenges across domains, including scalability, privacy, fairness, explainability, and data sparsity, and discusses how modern approaches like GNNs, LLMs, SSL, and multimodal fusion address them. It also maps RS applications across e-commerce, entertainment, health, tourism, finance, and beyond, and advocates stronger academia-industry collaboration, responsible AI practices, and evaluation beyond accuracy to guide future research and deployment efforts.
Abstract
Recommender Systems (RS) play an integral role in enhancing user experiences by providing personalized item suggestions. This survey reviews the progress in RS inclusively from 2017 to 2024, effectively connecting theoretical advances with practical applications. We explore the development from traditional RS techniques like content-based and collaborative filtering to advanced methods involving deep learning, graph-based models, reinforcement learning, and large language models. We also discuss specialized systems such as context-aware, review-based, and fairness-aware RS. The primary goal of this survey is to bridge theory with practice. It addresses challenges across various sectors, including e-commerce, healthcare, and finance, emphasizing the need for scalable, real-time, and trustworthy solutions. Through this survey, we promote stronger partnerships between academic research and industry practices. The insights offered by this survey aim to guide industry professionals in optimizing RS deployment and to inspire future research directions, especially in addressing emerging technological and societal trends\footnote. The survey resources are available in the public GitHub repository https://github.com/VectorInstitute/Recommender-Systems-Survey. (Recommender systems, large language models, chatgpt, responsible AI)
