ccMarvin vs underfoot

Marvin watches every company you back, private or public, and delivers the signals that matter: exec changes, acquisitions, product releases, funding rounds. Straight to...

Apple and Google swap the AI models inside your phone with OS updates.

About ccMarvin

Marvin watches every company you back, private or public, and delivers the signals that matter: exec changes, acquisitions, product releases, funding rounds. Straight to your inbox. Research, summaries, planning help, and life analysis, delivered to your inbox. 2026-09-07, Teased the Grok 5 training run, "biggest cluster yet", and said the Cybercab line is running ahead of schedule. 2026-09-06, Essay follow-up: interpretability results are moving into production Claude models.

About underfoot

Apple and Google swap the AI models inside your phone with OS updates. underfoot freezes one prompt suite, captures every OS build's answers, and publishes exactly what moved. Once a build is superseded, its model can never be measured again: every trace below is history that cannot be re-taken. All 140 macOS runs succeeded and every prompt returned byte-identical output across its 5 greedy runs, including the creative canaries (the haiku never varied). Any future change on this platform is the OS's doing, not sampling noise.