Engineering notes from 9io.
How we build products, AI systems and trading infrastructure — and what we learn on the way. Written by the people who do the work, with the sources linked.
Every major LLM API compared on price and benchmarks (October 2026)
Prices per million tokens, independent benchmark scores, speed and context limits for 23 models from 11 labs, with worked cost examples. As of 8 October 2026.
8 October 2026 · 16 min read AI industryWhat EU and California law now require of AI-generated content
Article 50 of the EU AI Act and California’s AI Transparency Act took effect on 2 August 2026. What product teams must build, and by when.
8 October 2026 · 13 min read AI industryAI agent containment lessons from the summer 2026 incidents
Lab agents reached real systems and MCP tools turned on their users. What failed in each 2026 incident, and the controls to enforce outside the model.
8 October 2026 · 12 min read AI engineeringAI decision models like Jev, and when to use one instead of an LLM
What an AI decision model like Jev is, how it differs from an LLM, the options as of 7 October 2026, what independent tests found, and when to use each.
7 October 2026 · 17 min read AI industryMigrating MCP servers and clients to the stateless 2026-07-28 spec
MCP’s 2026-07-28 revision drops sessions and the initialize handshake. What breaks, which clients support it in October 2026, and how to migrate safely.
6 October 2026 · 13 min read AI engineeringClaude Code cost per month, per engineer, and how to cap the bill
Claude Code cost per month per engineer, Codex and Cursor plans compared, which spending caps are hard, and a policy template. As of 5 October 2026.
5 October 2026 · 18 min read Product engineeringHow to take a vibe-coded app from Lovable to production safely
Moving a vibe-coded app from Lovable to production: the Supabase RLS, key, storage and webhook checks that matter, how to migrate, and when to rebuild.
4 October 2026 · 19 min read Product engineeringWhat a fractional CTO costs in 2026, and when an AI startup needs one
Fractional CTO cost in 2026: the market hourly rate, what a full-time CTO costs once employer costs are added, and a decision rule by startup stage.
3 October 2026 · 14 min read