Laguna S 2.1 solves a hard algorithm problem after 60k+ thinking tokens

I'm impressed by Laguna S 2.1

A user tested Laguna S 2.1 on a Union-Find data rearrangement problem that took them days to solve, requiring a Julia implementation with zero dynamic allocation. Qwen 3.5-122B and 3.6-27B both failed. Laguna produced 60k+ thinking tokens and eventually wrote passing code, though it relied on packing two integers into a 64-bit value. Multiple commenters report reasoning loops when context exceeds ~50k tokens; forcing yarn-attn-factor to 1.0 helps, but tool calling remains unreliable.

Why it matters: First-person experiment with concrete problem, model comparison, and failure/success details — not a generic review. But it's a single Reddit post, not an official release or cross-source event, so authority is limited. Scored at featured threshold 72.