AI Architecture

The race for larger context windows has defined LLM development for years. From GPT-4’s 128K tokens to Gemini’s 1M and beyond, the assumption has been simple: more context equals better performance. But a January 2026 paper from MIT CSAIL challenges this assumption entirely. Recursive Language Models (RLMs) don’t expand the context window—they render it irrelevant by treating prompts as external environments that models can programmatically explore, decompose, and recursively process. ...

When you ask ChatGPT about your company’s internal documents, it hallucinates. When you ask about events after its training cutoff, it fabricates. These aren’t bugs—they’re fundamental limitations of parametric knowledge encoded in model weights. Retrieval-Augmented Generation (RAG) emerged as the solution, but naive implementations fail spectacularly. This deep dive explores how to architect RAG systems that actually work. The Knowledge Encoding Problem Large Language Models encode knowledge in two ways: parametric (weights) and non-parametric (external data). Parametric knowledge is fast but frozen at training time, prone to hallucination, and impossible to update without retraining. Non-parametric knowledge—RAG’s domain—solves all three problems at the cost of latency and complexity. ...