PROMIT NOW · ALL SIX LENSES · 2026-03-15

◆ DAILY BRIEFING

Sunday, March 15, 2026

6 angles · 38 sources · 7,984 words · ~40 min end to end

  1. Engineer 6 sources · 6 min

    Context windows are physically stuck at 1M tokens for 2–5 years — the bottleneck is global HBM/DRAM supply, not algorithmic limits.

    Context windows are stuck at 1M tokens for years due to physical memory constraints, not algorithmic ones — so stop treating RAG as a temporary workaround and start treating it like a database schema.…

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  2. Security 6 sources · 7 min

    OpenAI's Codex agent — now in VS Code, JetBrains, and Xcode with 5x usage growth in 2026 — gives AI direct terminal access on developer machines through OS-specific sandboxes, but forking the open-source harness with a non-OpenAI model strips all model-level safety guardrails while preserving the shell.

    AI coding agents now have terminal access to developer machines, self-modifying instruction files in your repos, and OAuth tokens to your GitHub org — and they grew 5x this year while Meta simultaneou…

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  3. Data Science 6 sources · 7 min

    MIT-adjacent researchers claim that adding Gaussian noise to pretrained weights and ensembling the variants matches or exceeds GRPO/PPO across reasoning, coding, chemistry, and VLM tasks — implying your entire RL post-training pipeline may be drastically over-engineered.

    MIT researchers claim that adding Gaussian noise to pretrained model weights and ensembling the variants matches RL post-training (GRPO/PPO) across five task categories — a 2-day reproduction experime…

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  4. Product 6 sources · 7 min

    BCG just published the number every PM building AI features needs: productivity reverses beyond 3 simultaneous AI tools and 10% of work hours — users spend 2x more time on email and 9% less on deep work past that threshold.

    BCG quantified what every PM suspected but couldn't prove: the fourth AI tool makes workers worse, not better, with a hard ceiling at 10% of work hours — while frontier context windows are physically…

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  5. Leader 7 sources · 7 min

    BCG just published the first rigorous data showing AI productivity reverses at exactly 3 simultaneous tools and 7-10% of work hours — beyond that, workers hit 'AI brain fry' with 2x more email and 9% less focused work.

    AI just got its first hard constraints: BCG quantifies productivity peaking at 3 tools and 7-10% of work hours (more is toxic), context windows are hardware-locked at 1M tokens for 2-5 years, and the…

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  6. Investor 7 sources · 6 min

    BCG research reveals enterprise AI adoption has a hard cognitive ceiling — productivity reverses at 4+ simultaneous tools, and optimal usage is just 7-10% of work hours.

    BCG research reveals AI productivity reverses after 3 tools and 10% of the workday — a biological ceiling that enterprise AI valuations haven't priced in — while OpenAI's Codex grew 5x in three months…

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