go.dev/blog (Junyang Shao + David Chase, Oct 2) — Go 1.27 expands experimental GOEXPERIMENT=simd beyond amd64-only (Go 1.26): the new simd/archsimd package adds arm64 (NEON; SVE/SVE2 coming) + wasm 128-bit SIMD. ToArch/FromArch bridge portable ↔ arch types; sensible operation names (Add, ShiftAllLeft); Go 1.27 reshape API (ToBits/ReshapeToUint*s); Mask* ops + peepholes. Distinct from the HARD-SKIPPED Platform-independent SIMD (/blog/simd-experiment, briefed 09-25) — this is the arch-specific expansion primary, not a rehash of the portable API design post.

arXiv (Google + UMass) — Stateful contextual policy for agent tool use: regex over tool-call sequences + variable binding/predicates + deferred holes + scoped semantic checks; a reference monitor on every tool call. AgentDojo utility parity; analytical hijack defense 93–95% AgentDojo / 62–85% Toolathlon. Limits: NOT injection-proof if the user prompt is compromised; no public code in the abstract.

Jane Street Blog (Adam Yi, Oct 2) — Planned cabinet partitions of 15–25 min exposed six stacked bugs: glibc res_init segfault; UDP socket leak; Async Tcp.connect_sock timeout excludes DNS (since 2012); Kafka client retry without cancel; bootstrap discovery herd; systemd FD soft-limit 262144→32768. ~27k abandoned attempts; TCP herd ~474k. Lessons: timeout≠cancellation; failure-atomic multi-step setup; hypothesis must predict a number; model resources at shared scope.