2026 in LLMs (so far)
Simon Willison's Weblog (LLM / AI engineering) · Sep 27, 2026
Claim: 2026 has seen coding agents (Claude Code + Codex) mature from unreliable to production-ready; Claude Opus 4.5 and GPT-5.1 (Nov 2025) crossed an inflection point where agentic coding moved from "often make mistakes" to "reliable enough to use on a day-to-day basis".
Evidence: Author (credible AI observer) gives first-person account of model evals and practical deployment experience; anecdotal benchmark (pelican-on-bicycle SVG generation); notes 40+ conference sessions on agent security/sandboxing as signal of maturation; personal testimony of sustained project delivery with agents; mentions specific model releases (Claude Opus 4.5, GPT-5.1) timed to Nov 2025.
Rationale
First-person observational account from credible source (Simon Wardley, long-time analyst/speaker) about the exact dual agents (CC+Codex) Timothy runs. Direct applicability to monorepo workflow. Evidence is reproducible signal (personal deployment experience across multiple projects Jan–Jun 2026, conference attendance as independent corroboration of maturity trend). Durability moderate: depends on model capability but pattern of agentic coding + orchestration survives minor version bumps. No commoditization lever cited. Hype marker: "invisible line" is unquantified superlative framing, though claim itself is grounded in observed behavior. Verdict TRACK (not INVEST yet because claim is observational rather than prescriptive; worth monitoring but not actionable without roadmap/release specifics).