Fermi

Fermi was famous for answering questions no one thought answerable — how many piano tuners in Chicago? — with nothing but logic and back-of-envelope estimation.

The Fermi agent does the same thing with operational data: sparse signals, incomplete records, partial logs. It doesn't wait for clean data. It estimates with principled uncertainty, flags what it can't know, and gives you a number you can act on.

Every Fermi answer comes with bounds. You see the estimate, the confidence, and the assumptions — not because we bolted it on, but because order-of-magnitude reasoning is the contract.

How many piano tuners are in Chicago? Don't guess. Estimate.— Fermi's seminar, University of Chicago