Ax Xuanfei Ren, Allen Nie, Tengyang Xie, Ching-An Cheng 3/17/2026

POLCA: Stochastic Generative Optimization with LLM

POLCA framework uses LLMs as optimizers to automatically improve complex systems like prompts and multi-turn agents through numerical rewards and text feedback.

Ax Kevin Taylor 3/17/2026

Directional Routing in Transformers

Introduces directional routing mechanism for transformer attention heads with learned suppression directions, analyzed via mechanistic interpretability.

HN AlonKejzman 3/16/2026

Reducing TTFT by CPUMaxxing Tokenization

Open-source Rust BPE tokenizer delivering 9.1x speedup over HuggingFace. Reduces TTFT by up to 40% on long-context agentic workloads.

HN Poudlardo 3/16/2026

Mistral Releases Leanstral

Leanstral: first open-source code agent for Lean 4 theorem prover. Addresses verification bottleneck in formal mathematics.

HN pember 3/16/2026

Mistral Small 4

Mistral Small 4 unified model combining reasoning, multimodal, and agentic coding capabilities in single architecture.