Why LLM Recommenders Will Be AI's Biggest Consumer App — Devansh Tandon, Meta
Source
AI Engineer
Author
AI Engineer
Date
Key takeaways · AI-distilled
Tandon notes that four of the world's 10 most-used apps are content feeds, and says feeds stay cheap to run because they decode pointers to existing content rather than generating every tokenThe chunk of text a model reads and writes in — roughly three-quarters of a word — and the unit AI usage is billed in.Full definition → themselves.
Tandon points to Instagram's Your Algorithm as an example of a steerable LLMA large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.Full definition →-era feed, where users can see and edit what the algorithm thinks they like.
His recipe for an LLM recommender: tokenize content with semantic IDs, train the model to be bilingual in English and the catalog, then post-train it to rank using chain-of-thoughtHaving a model write out intermediate reasoning steps before its answer, which markedly improves performance on hard problems.Full definition → reasoning you can read.
Tandon frames recommendation as four S-curves (traditional recsys, LLM-inspired, LLM-native and agentic) and argues recommenders scale like LLMs, with the field still early on that curve.
Terms in this piece · Glossary
LLM — A large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.
token — The chunk of text a model reads and writes in — roughly three-quarters of a word — and the unit AI usage is billed in.
chain-of-thought — Having a model write out intermediate reasoning steps before its answer, which markedly improves performance on hard problems.
Why it matters
Meta's Devansh Tandon explains how semantic-ID tokenization shrinks a 10,000-token Reel to about 10, making LLM-native recommenders up to 100x cheaper per hour of engagement than chat-style generation.